Fix: resolve CI composer/psalm configuration issues

[Rom1-B]

Checklist before requesting a review

Please delete options that are not relevant.

• I have performed a self-review of my code.
• I have added tests (when available) that prove my fix is effective or that my feature works.
• I have updated the CHANGELOG with a short functional description of the fix or new feature.
• This change requires a documentation update.

Description

• It fixes #N/A
• This PR fixes the CI pipeline by removing an unneeded dev dependency from composer.json, adding an autoloader suffix to avoid class collisions, and configuring a dedicated Psalm cache directory.

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