Prevent ForbidMethodDeclaration sniff aborting on deprecated traits

[alies-dev]

Problem

On PHP 8.5 the #[\Deprecated] attribute is now honoured on traits. Loading a class that uses a deprecated trait emits a runtime deprecation (e.g. Trait X used by Y is deprecated, ...). In PHP 8.4 the attribute on a trait was a no-op, so nothing fired.

ForbidMethodDeclarationSniff::process() resolves the analysed class via is_subclass_of() / method_exists(), both of which autoload it. That autoload materialises the deprecated-trait usage, the deprecation fires, PHP_CodeSniffer turns it into an exception, and the whole file check aborts:

error - An error occurred during processing; checking has been aborted.
The error message was: Trait App\Http\Requests\RequestInviteAware used by
App\Http\Requests\InviteAwareRequest is deprecated, Please inject services
instead. ... The error originated in the
IxDFCodingStandard.Classes.ForbidMethodDeclaration sniff on line 34.
(Internal.Exception)

Any class under analysis that uses a #[\Deprecated] trait (or extends a deprecated class) hits this.

Fix

The deprecation is a side effect of the analysed code, not an issue with the sniff, so the sniff must not let it abort the run. The two reflection calls are moved into a private helper that silences E_DEPRECATED / E_USER_DEPRECATED (via a scoped set_error_handler restored in a finally) while resolving the class. Behaviour is otherwise identical.

Tests

Added ForbidMethodDeclarationSniffTest with fixtures where the analysed class uses a #[\Deprecated] trait. The regression test installs its own deprecation-capturing handler around the run and asserts none leak, so it fails on the unpatched sniff (with the exact PHP 8.5 trait-deprecation message) and passes after the fix. Verified against the real IxDF-web codebase: a full phpcs scan goes from 10 Internal.Exception failures to a clean run.