Skip constructor defaults on extensible classes

[Junaid-PK]

Fixes rectorphp/rector#9837

Summary

• skip InlineConstructorDefaultToPropertyRector for non-final classes
• preserve a declared property default when a child class bypasses the parent constructor
• add a regression fixture covering that inheritance path

The transformation moves initialization from runtime constructor flow to object creation. For an extensible class, a child can omit parent::__construct(), so moving the assignment changes observable behavior. The rule documentation and existing positive fixtures already use final classes; this makes that safety boundary explicit.

Verification

• targeted rule suite: 20 tests, 21 assertions
• full PHPUnit suite: 5,407 tests, 6,926 assertions, 2 skipped
• full PHPStan analysis: no errors
• ECS on both changed files: no errors