gazebo9,11 bottles broken by dartsim 6.12.1

[scpeters]

The minor version of dartsim in homebrew-core was recently upgraded from 6.11.1 to 6.12.1 in Homebrew/homebrew-core#89141, which has broken our gazebo bottles:

• https://build.osrfoundation.org/job/gazebo-install-one_liner-homebrew-amd64/2234/

We should open separate pull requests to bump the revision for gazebo9 and gazebo11 and rebuild the bottles. To do this, on a new branch run the following command for gazebo11:

brew bump-revision gazebo11 --message="for dartsim"

push the branch, open a pull request, and comment build bottle.

Then do the same for gazebo9.

[nkalupahana]

^ can confirm, this has broken our builds that use gazebo11: https://github.com/nkalupahana/ros2-foxy-macos/runs/4176692550?check_suite_focus=true

[nkalupahana]

All fixed for me!