Remove mismatched_lifetime_syntaxes allow lint in interop tests

[LucioFranco]

With 1.89 the protobuf gen crate is generating code that throws this warning. We should get protobuf to fix this then remove the lint from our code.

cc @dfawley @acozzette

[LucioFranco]

Example CI failure https://github.com/hyperium/tonic/actions/runs/16804016228/job/47592856455

[LucioFranco]

PR for the temp workaround https://github.com/hyperium/tonic/pull/2382

[dfawley]

I filed https://github.com/protocolbuffers/protobuf/issues/23057 for the protobuf team to address this. We can leave this open as a reminder to remove the workaround.

[dfawley]

FYI protocolbuffers/protobuf#23057 was marked as fixed. I'm not sure if we need to wait for a release or what.