Upgrade to PHP 8.x

[byjg]

This pull request introduces several changes to enhance the codebase's type safety, improve dependency management, and add static analysis capabilities. The most significant changes include adding Psalm for static analysis, updating dependencies, and refining type hints across various database classes.

Static Analysis and Dependency Management:

• Added Psalm for static analysis:
  • Updated .github/workflows/phpunit.yml to include Psalm (./vendor/bin/psalm).
  • Added Psalm configuration file psalm.xml.
  • Created a run configuration for Psalm in .idea/runConfigurations/Psalm.xml.
  • Updated composer.json to include vimeo/psalm as a development dependency and added autoload-dev section.

Type Hinting and Code Refinement:

• Enhanced type hinting and method signatures:

  • Refined type hints for properties and methods in src/Database/AbstractDatabase.php, including changing method signatures to specify return types and parameter types. [1] [2] [3]
  • Updated src/Database/DatabaseInterface.php to include type hints for method parameters and return types.

• Consistent exception handling and import statements:

  • Standardized exception handling and import statements across various database classes (DblibDatabase, MySqlDatabase, PgsqlDatabase, SqliteDatabase). [1] [2] [3] [4]

Breaking changes

• Added enum MigrationStatus, instead of const Migration::VERSION_*