Re-enable ign-launch Windows jobs

[chapulina]

These jobs were disabled on #213 because they were failing.

We're currently putting time into fixing Windows compilation of all Ignition libraries, so we should be able to re-enable CI soon.

This task is about making sure that the jobs are all good from the infrastructure side. The code-side fix is covered by gazebosim/gz-sim#168 and gazebosim/gz-launch#89 respectively.

One thing we may want to do is removing DART as a required dependency of ign-gazebo on Windows so that this is not blocked by gazebosim/gz-physics#87.

This issue also depends on gazebosim/gz-common#122.

[chapulina]

These are the jobs:

• Citadel
  • https://build.osrfoundation.org/job/ign_gazebo-ign-3-win/
  • https://build.osrfoundation.org/job/ign_launch-ign-2-win/
• Dome
  • https://build.osrfoundation.org/job/ign_gazebo-ign-4-win/
  • https://build.osrfoundation.org/job/ign_launch-ign-3-win/

[chapulina]

Reopening because we still need ign-launch