Add Symfony 7 support

[ttomdewit]

Add ^7.0 version constraint to Symfony Cache and Symfony HTTP foundation packages.

Summary

Simply extending the version constraint in composer.json.

Explanation

I need to see if I can extend the Github Actions if required.

Checklist

• I have provided a summary and an explanation
• I have reviewed the PR myself and left comments to provide context
• I have covered the changes with tests as appropriate - N/A
• I have made sure static analysis and other checks are successful

[ttomdewit]

As far as I can tell from Github Actions YAML definition I do not need to touch it to address the ^7.0 constraint.

[ttomdewit]

I ran all composer scripts as per CONTRIBUTING:

1. docker run --rm -v "$(pwd):/app" -w /app composer:2 install
2. docker run --rm -v "$(pwd):/app" -w /app composer:2 fix
3. docker run --rm -v "$(pwd):/app" -w /app composer:2 type
4. docker run --rm -v "$(pwd):/app" -w /app composer:2 test

During the composer fix run some deprecations were made visible which I thought I'd share:

Detected deprecations in use:
- Rule "function_typehint_space" is deprecated. Use "type_declaration_spaces" instead.
- Rule "native_function_type_declaration_casing" is deprecated. Use "native_type_declaration_casing" instead.
- Rule "no_unneeded_curly_braces" is deprecated. Use "no_unneeded_braces" instead.

[osteel]

Thanks for your contribution @ttomdewit!

I need to check why symfony/psr-http-message-bridge was set to version ^2.0.1 so far but in any case that's not an issue with this PR.

Thanks for pointing out the deprecations as well, will have a look