Fix PHP 8.2 CI install failure by stabilizing Composer lock resolution

[Copilot]

test (8.2) failed before test execution because composer.lock had drifted to PHP 8.4-only transitive dependencies (Symfony 8.x), making composer install unsatisfiable on PHP 8.2. This change re-aligns dependency resolution with the project’s supported runtime floor so the lock remains installable across the CI matrix.

• Root cause addressed: lockfile/runtime mismatch

  • composer.lock contained packages requiring php >=8.4.1 while CI validates 8.1/8.2/8.3/8.4.

• Dependency resolution constrained to supported floor

  • Added Composer platform pin in composer.json so dependency solving targets the minimum supported runtime.

• Lockfile regenerated under the platform constraint

  • Updated composer.lock to compatible transitive versions (notably Symfony and PHPUnit dependency graph), removing PHP 8.4-only lock entries for shared CI jobs.

{
  "config": {
    "platform": {
      "php": "8.1.0"
    }
  }
}