Drop doctrine/orm 2 support

[sylfabre]

Why

All applications consuming this bundle now run doctrine/orm 3, so the ORM 2 compatibility layer is dead weight.

Changes

• composer.json: doctrine/orm constraint narrowed from ^2.20|^3.0 to ^3.0.
• EntityValidator:
  • field mappings are always ORM 3 FieldMapping objects now — the is_array() detection is gone, get_object_vars() keeps normalizing to the array shape providers expect;
  • association handling rewritten on ORM 3's semantic helpers (isToOneOwningSide() / isOwningSide()) instead of the ORM 2 array branch + bitmask checks, removing the extractAssociationMappingValues() tuple helper and its @codeCoverageIgnore;
  • the DomainException('Unknown type') branch is removed: ORM 3's AssociationMapping::type() is final and can only return one of the four known constants, so the branch was unreachable dead code.
• FieldConstraintsSetProviderInterface: contract docblock updated (no more "ORM 2 array shape" wording).
• Tests: the mock metadata now uses real ORM 3 mapping objects (FieldMapping, EmbeddedClassMapping, association mapping classes); the ORM 3-specific duplicate tests, the skipUnlessOrm3() guard and the unknown-type test (dead branch) are removed.
• phpstan.neon.dist: all dual-major ignore rules and reportUnmatchedIgnoredErrors: false are removed; one narrow argument.type ignore remains for the minimal test fixture arrays fed to fromMappingArray().

Net: −155 lines.

Validation

Ran in a PHP 8.4 container with highest deps: composer validate --strict, PHPUnit (287 tests OK, 4 expected skips), PHPStan (0 errors), PHPCS (clean), Rector dry-run (clean).

🤖 Generated with Claude Code

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
100.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
100.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud