Switching to single-platform build per PR comments

ci/cmake.yml

@@ -8,11 +8,11 @@ env:
 
 jobs:
   build:
-
-    runs-on: ${{ matrix.os }}
-    strategy:
-      matrix:
-        os: [windows-latest, ubuntu-latest, macOS-latest]
+    # The CMake configure and build commands are platform agnostic and should work equally
+    # well on Windows or Mac.  You can convert this to a matrix build if you need
+    # cross-platform coverage.
+    # See: https://docs.github.com/en/actions/configuring-and-managing-workflows/configuring-a-workflow#configuring-a-build-matrix
+    runs-on: ubuntu-latest
 
     steps:
     - uses: actions/checkout@v2