Remove unnecessary google test import in CI once upstream is resolved

[timsaucer]

Describe the bug
After MaterializeInc/rust-protobuf-native#20 is resolved, remove the temporary CI lines marked in

• .github/workflows/build.yml
• .github/workflows/test.yaml

To Reproduce
If you remove those lines, CI currently fails due to the linked issue above.

Expected behavior
CI should pass without needing to install google test suite.

Additional context
These lines were added as a temporary work around for CI.