Suppress deprecated warnings for weak field options internally (#25305)

Suppress deprecated warnings for weak field options in internal source code.

The `FieldOptions::weak` field was marked deprecated, but it is used in several places internally in reflection-related code. Since this must be supported for backward compatibility, I figured the only practical thing to do is to suppress deprecation warnings wherever that field is used.

Closes #25305

COPYBARA_INTEGRATE_REVIEW=https://github.com/protocolbuffers/protobuf/pull/25305 from mikael-s-persson:fix/ignore_deprecated_internally 6227aa9c4b547288f29469f4516d8dd1ca4283c9
PiperOrigin-RevId: 919308499