A warning line should look like a warning section

[ci skip]
Cleanup loaded features and constants after dependency tests.
Explicit route test class

shows the class that the test must extend in order to have the assert_routing method available
[ci skip] Add Doc of with_options for the case when inherited default options and original options have same keys
Fix that a collection proxy could be cached before the save of the owner, resulting in an invalid proxy lacking the owner’s id.

Absent this fix calls like: owner.association.update_all to behave unexpectedly because they try to act on association objects where
owner_id is null.

more evidence here: https://gist.github.com/Empact/5865555
```
Active Record 3.2.13
-- create_table(:firms, {:force=>true})
   -> 0.1371s
-- create_table(:clients, {:force=>true})
   -> 0.0005s
1 clients. 1 expected.
1 clients updated. 1 expected.
```

```
Active Record 4.0.0
-- create_table(:firms, {:force=>true})
   -> 0.1606s
-- create_table(:clients, {:force=>true})
   -> 0.0004s
1 clients. 1 expected.
0 clients updated. 1 expected.
```
FileHandler should not be called for files outside the root

FileHandler#matches? should return false for files that are outside the
"root" path.
Clarify `#update_all` doc about value processing

This clarify the fact that `#update_all` doesn't type-cast passed
values and that these values are written as-is in the SQL DB.

Fix #17242

[ci skip]
Add #key? to ActiveModel::Errors

Mirror Ruby's Hash#key?
Merge pull request #17252 from Bounga/update_all_doc_clarification

[ci skip] Clarify `#update_all` doc about values processing
Merge pull request #17253 from gshutler/activemodel-errors-key

Add #key? to ActiveModel::Errors
Improve Journey compliance to RFC 3986

The scanner in Journey fails to recognize routes that use literals
from the sub-delims section of RFC 3986.

This commit enhance the compatibility of Journey with the RFC by
adding support of authorized delimiters to the scanner.

Fix #17212
ActionController::InvalidCrossOriginRequest fails with 422 instead of 500
Fixes #15967
Merge pull request #17220 from Bounga/fix_journey_rfc_3986_compliance

Improve Journey compliance to RFC 3986
Use `#tr` instead of `#gsub`

`#tr` is more efficient than `#gsub` and can be used as a drop in
replacement in this context.
break cache if we're inside a "scoping" call. fixes #17052

For now, we don't want to take "scoping" calls in to account when
calculating cache keys for relations, so just opt-out.
make sure cache is not used for collection assocations too

follow up for #17052
:scissors: duplicated `require`s
Make the config actually copyable

The intention here is to make the required config copy-able from the console/logs, so add a newline at the end of the message to make that easier. (Otherwise it would be `... raise_in_transactional_callbacks = true (called from...`.)
delete leftover JoinOperation struct
Add ActiveJob to "Welcome to Rails" section

[ci skip]