Add support for Jazzy

[christophebedard]

We need to use the testing apt repo to get Jazzy binaries for tests before Jazzy is officially released. See: https://docs.ros.org/en/jazzy/Installation/Ubuntu-Install-Debians.html#enable-required-repositories. Once Jazzy has been released, we can revert this.

Users will need to use use-ros2-testing: true for Jazzy.

I won't mention Jazzy in the README until it's officially been released

Relates to ros-tooling/action-ros-ci#863
Relates to ros-tooling/setup-ros-docker#71

[christophebedard]

https://github.com/ros-tooling/setup-ros/actions/runs/8838552286/job/24269960443?pr=673#step:6:2112

  The following packages have unmet dependencies:
   ros-rolling-pcl-conversions : Depends: libpcl-common1.13 but it is not installable
                                 Depends: libpcl-io1.13 but it is not installable
  E: Unable to correct problems, you have held broken packages.

This is an unrelated issue that should be fixed soon.