Fix more instances of gz-cmake4

[chapulina]

🦟 Bug fix

• Follow up to ⬆️ Bump main to 4.0.0~pre1 #296
• Part of Release Garden gazebo-tooling/release-tools#578

Summary

More instances noticed by @jennuine .

That's why we need our examples to be compiled with our test suite 🙃

Checklist

• Signed all commits for DCO
• Added tests
• Updated documentation (as needed)
• Updated migration guide (as needed)
• Consider updating Python bindings (if the library has them)
• codecheck passed (See contributing)
• All tests passed (See test coverage)
• While waiting for a review on your PR, please help review another open pull request to support the maintainers

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.

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[chapulina]

• ⬆️ Bump main to 4.0.0~pre1 (part 2) #298