Bumps in ionic: use gz-cmake4

[azeey]

See gazebo-tooling/release-tools#1027

[scpeters]

homebrew is passing

Ubuntu needs nightly builds of gz-cmake4

[codecov]

Codecov Report

Merging #111 (5f1f4f0) into main (15e1571) will not change coverage.
The diff coverage is n/a.

❗ Current head 5f1f4f0 differs from pull request most recent head aa6a929. Consider uploading reports for the commit aa6a929 to get more accurate results

@@           Coverage Diff           @@
##             main     #111   +/-   ##
=======================================
  Coverage   80.11%   80.11%           
=======================================
  Files           8        8           
  Lines         342      342           
=======================================
  Hits          274      274           
  Misses         68       68