minor #3178 Fix CI when testing Symfony RCs versions (Kocal)

This PR was merged into the 2.x branch.

Discussion
----------

 Fix CI when testing Symfony RCs versions

| Q              | A
| -------------- | ---
| Bug fix?       | yes
| New feature?   | no <!-- please update src/**/CHANGELOG.md files -->
| Deprecations?  | no <!-- if yes, also update UPGRADE-*.md and src/**/CHANGELOG.md -->
| Documentation? | no <!-- required for new features, or documentation updates -->
| Issues         | Fix #... <!-- prefix each issue number with "Fix #", no need to create an issue if none exist, explain below instead -->
| License        | MIT

<!--
Replace this notice by a description of your feature/bugfix.
This will help reviewers and should be a good start for the documentation.

Additionally (see https://symfony.com/releases):
 - Always add tests and ensure they pass.
 - For new features, provide some code snippets to help understand usage.
 - Features and deprecations must be submitted against branch main.
 - Update/add documentation as required (we can help!)
 - Changelog entry should follow https://symfony.com/doc/current/contributing/code/conventions.html#writing-a-changelog-entry
 - Never break backward compatibility (see https://symfony.com/bc).
-->

We are waiting for Symfony 8 compatibility for zenstruck/console-test & spatie/phpunit-snapshot-assertions, but that's fine.

Commits
-------

6ba0823 Fix CI when testing Symfony RCs versions

Author: Kocal

.github/workflows/unit-tests.yaml

@@ -48,10 +48,13 @@ jobs:
                     # Explicit Symfony versions
                     -  php-version: '8.2'
                        symfony-version: '^7.4.0-RC1' # TODO: change to '7.4.*' when Symfony 7.4 is released
+                       minimum-stability: 'RC'
                     -  php-version: '8.4'
                        symfony-version: '^8.0.0-RC1' # TODO: change to '8.0.*' when Symfony 8.0 is released
+                       minimum-stability: 'RC'
                     -  php-version: '8.5'
                        symfony-version: '^8.0.0-RC1' # TODO: change to '8.0.*' when Symfony 8.0 is released
+                       minimum-stability: 'RC'
 
         env:
             SYMFONY_REQUIRE: ${{ matrix.symfony-version || '>=5.4' }} # TODO: To change to '>=6.4' in 3.x