[TomasVotruba]

Deprecate DeclareStrictTypesRector - adding declare(strict_types=1) without any context about type safety is too risky: it can flip loose scalar coercions into TypeError at runtime.

Use SafeDeclareStrictTypesRector instead, which only adds the declare to files that are already type-safe (no scalar type coercions).

Changes:

• gut the rule body to throw, mark with DeprecatedInterface + @deprecated
• remove it from the rector-preset set
• drop its tests and the now-orphaned File::hasShebang() helper