Adds -O2 flag to bazel build.

[agalbachicar]

🦟 Bug fix

Summary

Adds -O2 flag to bazel build to reduce execution time of tests. See https://github.com/maliput/maliput_malidrive/pull/252#issuecomment-1818816657 for an example of the failures we face.

Checklist

• [x] Signed all commits for DCO
• [ ] Added tests
• [ ] Updated documentation (as needed)
• [ ] Updated migration guide (as needed)
• [ ] Consider updating Python bindings (if it affects the public API)

Note to maintainers: Remember to use Squash-Merge and edit the commit message to match the pull request summary while retaining Signed-off-by messages.

[agalbachicar]

This is certainly not enough, but it won't block CI.

[francocipollone]

Going in