storage: TestIntegration_Copy failed

[flaky-bot]

Note: #8259 was also for this test, but it was closed more than 10 days ago. So, I didn't mark it flaky.

---

commit: 31558c7
buildURL: Build Status, Sponge
status: failed

[flaky-bot]

Looks like this issue is flaky. 😟

I'm going to leave this open and stop commenting.

A human should fix and close this.

---

When run at the same commit (31558c7), this test passed in one build (Build Status, Sponge) and failed in another build (Build Status, Sponge).

[tritone]

Failed in one gRPC case only after 30s.

    --- FAIL: TestIntegration_Copy/grpc (35.04s)
        --- PASS: TestIntegration_Copy/grpc/copy_within_bucket (0.43s)
        --- PASS: TestIntegration_Copy/grpc/copy_to_new_bucket (0.42s)
        --- PASS: TestIntegration_Copy/grpc/copy_with_attributes (0.40s)
        --- FAIL: TestIntegration_Copy/grpc/copy_to_new_region (30.03s)
    integration_test.go:1873: Copier.Run failed with rpc error: code = DeadlineExceeded desc = Deadline expired before operation could complete.