Repository: flutter
Issue: `DartUri: Cannot read packages spec` in workspace environment
Labels: tool,has reproducible steps,P1,team-tool,triaged-tool,found in release: 3.27,found in release: 3.28

### Steps to reproduce

Short: Create a flutter project inside a workspace and add a web target.

1. Create an empty folder
2. Add a `pubspec.yaml` with a `name` and `workspace` attribute
3. Create a subfolder using `flutter create --platforms=web -e app`
4. Add `resolution: workspace` to its `pubspec.yaml` and the package directory to the root pubspec
5. Run the project in web

### Expected results

Not to print anything (-> not to throw errors)

### Actual results

```
DartUri: Cannot read packages spec: file:///C:/Users/jakob/Documents/GitHub/upsheep/packages/test_app/.dart_tool/package_config.jsonError: PathNotFoundException: Cannot open file, path = 'C:\Users\jakob\Documents\GitHub\upsheep\packages\test_app\.dart_tool\package_config.json' (OS Error: Das System kann die angegebene Datei nicht finden., errno = 2)
```
(second part is German and means something along the lines of "The system could not find the specified file")

I did some digging and by judging by previous issues, I believe this is an issue directly related to Flutter.
It occurs because `pub get` [deletes said `.dart_tool/package_config.json` file](https://dart.dev/tools/pub/workspaces#:~:text=Delete%20any%20other%20existing%20pubspec.lock%20and%20.dart_tool/package_config.json%20files%20next%20to%20workspace%20packages.) and "relocates" it to the root project.

Running the project still works, but on every refresh the error is printed. Not very cool

### Code sample

<details open><summary>Code sample</summary>

Not applicable, see "Steps to reproduce"

</details>


### Screenshots or Video

<details open>
<summary>Screenshots / Video demonstration</summary>

Not applicable

</details>


### Logs

The instructions say I have to add `--verbose`, it's quite a long output, so I also attached the output without verbose.

<details open><summary>Logs without Verbose</summary>

```console
C:\Users\jakob\Documents\GitHub\upsheep\packages\test_app>flutter run
Resolving dependencies in `C:\Users\jakob\Documents\GitHub\upsheep`...
Downloading packages...
  _fe_analyzer_shared 76.0.0 (78.0.0 available)
  analyzer 6.11.0 (7.1.0 available)
  async 2.11.0 (2.12.0 available)
  boolean_selector 2.1.1 (2.1.2 available)
  characters 1.3.0 (1.4.0 available)
  clock 1.1.1 (1.1.2 available)
  collection 1.19.0 (1.19.1 available)
  fake_async 1.3.1 (1.3.2 available)
  leak_tracker 10.0.7 (10.0.8 available)
  leak_tracker_flutter_testing 3.0.8 (3.0.9 available)
  matcher 0.12.16+1 (0.12.17 available)
  material_color_utilities 0.11.1 (0.12.0 available)
  meta 1.15.0 (1.16.0 available)
  path 1.9.0 (1.9.1 available)
  source_span 1.10.0 (1.10.1 available)
  stack_trace 1.12.0 (1.12.1 available)
  stream_channel 2.1.2 (2.1.4 available)
  string_scanner 1.3.0 (1.4.1 available)
  term_glyph 1.2.1 (1.2.2 available)
  test 1.25.8 (1.25.14 available)
  test_api 0.7.3 (0.7.4 available)
  test_core 0.6.5 (0.6.8 available)
  vm_service 14.3.0 (15.0.0 available)
Got dependencies in `C:\Users\jakob\Documents\GitHub\upsheep`!
23 packages have newer versions incompatible with dependency constraints.
Try `flutter pub outdated` for more information.
Launching lib\main.dart on Chrome in debug mode...
Waiting for connection from debug service on Chrome...             23,3s
DartUri: Cannot read packages spec: file:///C:/Users/jakob/Documents/GitHub/upsheep/packages/test_app/.dart_tool/package_config.jsonError:
PathNotFoundException: Cannot open file, path = 'C:\Users\jakob\Documents\GitHub\upsheep\packages\test_app\.dart_tool\package_config.json' (OS
Error: Das System kann die angegebene Datei nicht finden.
, errno = 2)
This app is linked to the debug service: ws://127.0.0.1:51345/YC9YGKFnjaI=/ws
Debug service listening on ws://127.0.0.1:51345/YC9YGKFnjaI=/ws

🔥  To hot restart changes while running, press "r" or "R".
For a more detailed help message, press "h". To quit, press "q".

A Dart VM Service on Chrome is available at: http://127.0.0.1:51345/YC9YGKFnjaI=
The Flutter DevTools debugger and profiler on Chrome is available at: http://127.0.0.1:9102?uri=http://127.0.0.1:51345/YC9YGKFnjaI=

Application finished.

C:\Users\jakob\Documents\GitHub\upsheep\packages\test_app>
```

</details>

<details open><summary>Logs with Verbose</summary>

This reveals a lot more DartUri errors than initially thought. Wow

> Too long, see https://pastebin.com/PGQN912h

</details>


### Flutter Doctor output

<details open><summary>Doctor output</summary>

```console
[√] Flutter (Channel stable, 3.27.1, on Microsoft Windows [Version 10.0.26100.2605], locale de-DE)
    • Flutter version 3.27.1 on channel stable at C:\flutter
    • Upstream repository https://github.com/flutter/flutter.git
    • Framework revision 17025dd882 (4 weeks ago), 2024-12-17 03:23:09 +0900
    • Engine revision cb4b5fff73
    • Dart version 3.6.0
    • DevTools version 2.40.2

[√] Windows Version (Installed version of Windows is version 10 or higher)

[√] Android toolchain - develop for Android devices (Android SDK version 35.0.0)
    • Android SDK at C:\Users\jakob\AppData\Local\Android\Sdk
    • Platform android-35, build-tools 35.0.0
    • Java binary at: C:\Program Files\Android\Android Studio\jbr\bin\java
    • Java version OpenJDK Runtime Environment (build 17.0.11+0--11852314)
    • All Android licenses accepted.

[√] Chrome - develop for the web
    • Chrome at C:\Program Files\Google\Chrome\Application\chrome.exe

[√] Visual Studio - develop Windows apps (Visual Studio Community 2022 17.10.4)
    • Visual Studio at C:\Program Files\Microsoft Visual Studio\2022\Community
    • Visual Studio Community 2022 version 17.10.35027.167
    • Windows 10 SDK version 10.0.22621.0

[√] Android Studio (version 2024.1)
    • Android Studio at C:\Program Files\Android\Android Studio
    • Flutter plugin can be installed from:
       https://plugins.jetbrains.com/plugin/9212-flutter
    • Dart plugin can be installed from:
       https://plugins.jetbrains.com/plugin/6351-dart
    • android-studio-dir = C:\Program Files\Android\Android Studio
    • Java version OpenJDK Runtime Environment (build 17.0.11+0--11852314)

[√] VS Code, 64-bit edition (version 1.96.2)
    • VS Code at C:\Program Files\Microsoft VS Code
    • Flutter extension version 3.102.0

[√] Connected device (2 available)
    • Windows (desktop) • windows • windows-x64    • Microsoft Windows [Version 10.0.26100.2605]
    • Chrome (web)      • chrome  • web-javascript • Google Chrome 131.0.6778.265

[√] Network resources
    • All expected network resources are available.

• No issues found!
```

</details>