Merge pull request csu-hmc#374 from moorepants/reduce-ci-matrix

Reduce combination of os and python versions tested in CI.

.github/workflows/tests.yml

@@ -17,6 +17,27 @@ jobs:
         # macos-13 is the last intel based runner
         os: [ubuntu-latest, macos-13, macos-latest, windows-latest]
         python-version: ['3.9', '3.10', '3.11', '3.12', '3.13']
+        # test all python versions on ubuntu, but only latest two on mac and
+        # windows
+        exclude:
+          - os: macos-13
+            python-version: '3.9'
+          - os: macos-13
+            python-version: '3.10'
+          - os: macos-13
+            python-version: '3.11'
+          - os: macos-latest
+            python-version: '3.9'
+          - os: macos-latest
+            python-version: '3.10'
+          - os: macos-latest
+            python-version: '3.11'
+          - os: windows-latest
+            python-version: '3.9'
+          - os: windows-latest
+            python-version: '3.10'
+          - os: windows-latest
+            python-version: '3.11'
     defaults:
       run:
         shell: bash -el {0}