mio 6603010c0d testing/grpcurl: fix test with go 1.25
Fix tls test cases with go 1.25.

```
--- FAIL: TestBrokenTLS_ClientNotTrusted (0.01s)
    tls_settings_test.go:257: expecting TLS certificate error, got: remote error: tls: handshake failure
--- FAIL: TestBrokenTLS_RequireClientCertButNonePresented (0.01s)
    tls_settings_test.go:297: expecting TLS certificate error, got: remote error: tls: handshake failure
FAIL
FAIL	github.com/fullstorydev/grpcurl	20.482s
ok  	github.com/fullstorydev/grpcurl/cmd/grpcurl	0.010s
?   	github.com/fullstorydev/grpcurl/internal/testing	[no test files]
?   	github.com/fullstorydev/grpcurl/internal/testing/cmd/bankdemo	[no test files]
?   	github.com/fullstorydev/grpcurl/internal/testing/cmd/testserver	[no test files]
?   	github.com/fullstorydev/grpcurl/internal/testing/jsonpb_test_proto	[no test files]
FAIL
>>> ERROR: grpcurl: check failed
```
2025-09-05 05:57:38 +00:00
..