fixes#25617
This pull request introduces a stricter check for parameter type
relations in the `procParamTypeRel` procedure. Specifically, it ensures
that two types are not only structurally equal but also have the same
backend type, taking type aliases into account.
Type relation checks:
*
[`compiler/sigmatch.nim`](diffhunk://#diff-251afcd01d239369019495096c187998dd6695b6457528953237a7e4a10f7138R787-R789):
In `procParamTypeRel`, added a check to ensure that if two types are
considered equal (`isEqual`), they must also have the same backend type
(using `sameBackendTypePickyAliases`). If not, the result is set to
`isNone`, preventing false positives when type aliases differ.