Update PHP requirements and improve code annotations

[dmolineus]

This pull request includes the following changes:

• Set PHP 7.4 as the minimum requirement and utilize native property types.
• Fixed issues reported by Psalm to improve static analysis.
• Adjusted handling of PHP version detection to avoid assumptions about PHP 8.x features while maintaining support for PHP 7.4.
• Enhanced code by adding annotations for method overrides.
• Used explicit nullables for silencing PHP 8.4 deprecations.

[discordier]

As usual, nit-picks.

On the pipeline errors:

• While psalm failure is expected in php 8.0 and 8.1, it should run in 7.4.
• The require-checker is failing in lower versions too.

[discordier]

Triggering the pipeline again pulled the correct psalm versions but now the psalm.xml is incompatible. Psalm 5.x does not know the ClassMustBeFinal element apparently.

Sidenote: PHP7.4 does phpcq install instead of update and therefore pulls the tools for current master - this seems to be wrong

[dmolineus]

Triggering the pipeline again pulled the correct psalm versions but now the psalm.xml is incompatible. Psalm 5.x does not know the ClassMustBeFinal element apparently.

I have no idea how to fix it properly.

[discordier]

Triggering the pipeline again pulled the correct psalm versions but now the psalm.xml is incompatible. Psalm 5.x does not know the ClassMustBeFinal element apparently.

I have no idea how to fix it properly.

The only idea I have is providing separate config files for different conflicting php versions.

[discordier]

Good to go - however the pipeline failures should get adressed by either:

• fixing them (what ever the way to go might be then)
• dropping support for end of life versions (which will break these then).

[dmolineus]

I vote for dropping support for end of life PHP versions. We would still have to support PHP 8.1. There is a broken psalm version used build against PHP 8.2. Haven't you release the version override for psalm already?

[discordier]

I vote for dropping support for end of life PHP versions. We would still have to support PHP 8.1. There is a broken psalm version used build against PHP 8.2. Haven't you release the version override for psalm already?

Yes, the overrides are in place and working.
They get correctly pulled when doing phpcq update - we do not validate the constraints on phpcq install though.