Update to Symfony 7

[javiereguiluz]

I don't understand the failing test. It says:

Verifying lock file contents can be installed on current platform.
Warning: The lock file is not up to date with the latest changes in composer.json. You may be getting outdated dependencies. It is recommended that you run `composer update` or `composer update <package name>`.
- Required package "symfony/phpunit-bridge" is not present in the lock file.
This usually happens when composer files are incorrectly merged or the composer.json file is manually edited.
Read more about correctly resolving merge conflicts https://getcomposer.org/doc/articles/resolving-merge-conflicts.md
and prefer using the "require" command over editing the composer.json file directly https://getcomposer.org/doc/03-cli.md#require-r
Error: Process completed with exit code 4.

BUT, symfony/phpunit-bridge is in the lock file:

https://github.com/symfony/demo/pull/1457/files#diff-f37acfaa6b11f575a9a6f41a75fa73a61d0f8ebc2c9b8cddc215d8aca10e44f5R8898

[dmaicher]

@javiereguiluz this seems related to https://github.com/sebastianbergmann/phpunit/issues/5578 and fixed by https://github.com/symfony/symfony/pull/52846

Maybe try using composer require symfony/phpunit-bridge "7.0.x-dev as 7.0.1" --dev to see if it works then

[javiereguiluz]

@dmaicher it worked! Thanks a lot 🙇