Drop support for EOL distros and Ubuntu Bionic

[christophebedard]

• Drop support for Melodic and Foxy, since they are now EOL
• Drop support for Ubuntu Bionic, since there is no longer an active ROS distro for it (used to be Melodic)
• Since there is no longer (and never will be) a common Ubuntu version for a ROS 1 distro and a ROS 2 distro, remove the test_multiple_ros_installations CI test job
• Update Windows binaries for Humble
• Update distros in README

[codecov]

Codecov Report

Patch coverage: 100.00% and no project coverage change.

Comparison is base (6c3a899) 93.18% compared to head (69c3b23) 93.18%.

❗ Current head 69c3b23 differs from pull request most recent head 263c477. Consider uploading reports for the commit 263c477 to get more accurate results

Additional details and impacted files

@@           Coverage Diff           @@
##           master     #592   +/-   ##
=======================================
  Coverage   93.18%   93.18%           
=======================================
  Files           8        8           
  Lines         176      176           
  Branches       17       17           
=======================================
  Hits          164      164           
  Misses         12       12           

Impacted Files	Coverage Δ
src/package_manager/apt.ts	93.75% <ø> (ø)
src/setup-ros-windows.ts	78.12% <ø> (ø)
src/setup-ros-linux.ts	97.72% <100.00%> (ø)
src/utils.ts	90.32% <100.00%> (ø)

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[emersonknapp]

I'm fine with this as long as Foxy/Melodic users can keep using old releases of this action to build their projects

[christophebedard]

Yep, users can just keep using an older version of setup-ros/action-ros-ci, but they of course won't get new features.