Deprecate source_macro

`source_macro` is no longer used in any ActiveRecord code. I've
chosen to deprecate it because it was not marked as nodoc and may
be in use outside of rails source.
rename MiniTest to Minitest
Merge pull request #16373 from eileencodes/deprecate-reflection-source_macro

Deprecate source_macro
Merge pull request #16374 from rajcybage/consistency_minitest

rename MiniTest to Minitest
[ci skip] fix markdown
Add an after_bundle callback in Rails templates

The template runs before the generation of binstubs – this does not
allow to write one, that makes an initial commit to version control.
It is solvable by adding an after_bundle callback.
Merge pull request #16377 from JackDanger/doc-fix-in-association-reflection

Fixes small error in ActiveRecord::Reflection docs
updating documented parameter for build_constraint

Updates documentation in line with changes made in
743b67508e2027e1d086142ccbec47a19fc943f6
Merge pull request #16378 from JackDanger/doc-fix-in-join-association-build_constraint

[doc] updating documented parameter for build_constraint
[ci skip] Remove "Machinist" from testing guide
Merge pull request #16380 from y-yagi/patch-1

[ci skip] Remove "Machinist" from testing guide
[ci skip] add tip for uglifier in execjs error
Merge pull request #16306 from aditya-kapoor/add-docs-for-uglifier

[ci skip] add tip for uglifier in execjs error
Generating stubs for helper tests is overly specific. Most helpers should simply be tested as part of the view thats using them. If you need something beyond that, you can add a test yourself for them
Change the production log level default from :info to :debug. All production apps I have ever worked with has done this. Let us reflect that default. You often want those SQL quieries to be able to debug issues in production
Stubs are no longer generated for helpers, so dont test for it
Update docs to reflect that helper stubs are no longer generated
A few more tests asserting the presence of helper test stubs
Using no_result_var in Journey's parser generator

Previously the generated parser had an intermediate local variable
`result` that really useful if you're building up a stateful object but
Journey always discards the result argument to the reduce functions.

This produces a simpler parser for anybody who actually wants to read
the thing.

Sadly, there's no real performance speedup with this change.
Merge pull request #16386 from JackDanger/journey-no-result-var

Using no_result_var in Journey's parser generator