Supress msvc dll exported interface warning

[Blast545]

Summary

Suppresses a warning appearing in the CI job for ign-launch5. Reference build: https://build.osrfoundation.org/job/gz_launch-ign-launch5-win/49/

This fix was applied to gz-launch here: https://github.com/gazebosim/gz-launch/pull/199/files#diff-c3f9cb0a10e4084bda0abece3428e80d90754073fc083b78887bfbcf6276bb07

cc: @Crola1702

Checklist

• [x] 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.