Chore: Update deprecated phpcs-fixer rules

[michael-schmetter]

Description

PHPCS-Fixer was complaining about deprecated rules. This PR fixes that and uses the recommended rules:

Before:

$ composer fixer  
> php-cs-fixer fix --verbose --allow-risky=yes
PHP CS Fixer 3.59.3 7th Gear by Fabien Potencier, Dariusz Ruminski and contributors.
PHP runtime: 8.3.7
Running analysis on 1 core sequentially.
You can enable parallel runner and speed up the analysis! Please see usage docs for more information.
Loaded config default from "/Users/schmetter/dev/unleash-client-php/.php-cs-fixer.dist.php".
Using cache file ".php-cs-fixer.cache".
 190/190 [▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓] 100%


Fixed 0 of 190 files in 0.497 seconds, 20.00 MB memory used

Detected deprecations in use:
- Option "tokens: use_trait" used in `no_extra_blank_lines` rule is deprecated, use the rule `class_attributes_separation` with `elements: trait_import` instead.
- Rule "compact_nullable_typehint" is deprecated. Use "compact_nullable_type_declaration" instead.
- Rule "function_typehint_space" is deprecated. Use "type_declaration_spaces" instead.
- Rule "no_trailing_comma_in_singleline_array" is deprecated. Use "no_trailing_comma_in_singleline" instead.
- Rule "single_blank_line_before_namespace" is deprecated. Use "blank_lines_before_namespace" instead.

After:

$ composer fixer
> php-cs-fixer fix --verbose --allow-risky=yes
PHP CS Fixer 3.59.3 7th Gear by Fabien Potencier, Dariusz Ruminski and contributors.
PHP runtime: 8.3.7
Running analysis on 1 core sequentially.
You can enable parallel runner and speed up the analysis! Please see usage docs for more information.
Loaded config default from "/Users/schmetter/dev/unleash-client-php/.php-cs-fixer.dist.php".
Using cache file ".php-cs-fixer.cache".
 190/190 [▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓] 100%


Fixed 0 of 190 files in 2.530 seconds, 20.00 MB memory used

Sidenote: First recommendation

Option "tokens: use_trait" used in `no_extra_blank_lines` rule is deprecated, use the rule `class_attributes_separation` with `elements: trait_import` instead.` 

is handled with the defaults of class_attributes_separation.

Type of change

Please delete options that are not relevant.

• Bug fix (non-breaking change which fixes an issue)

How Has This Been Tested?

Please describe the tests that you ran to verify your changes.

• Integration tests / Manual Tests

Checklist:

• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• Any dependent changes have been merged and published in downstream modules

[RikudouSage]

Looks good, thank you!