ci: build also on macOS

Author: herrernst

.github/workflows/build.yml

@@ -36,7 +36,7 @@ jobs:
     runs-on: ${{ matrix.os }}
     strategy:
       matrix:
-        os: [ubuntu-latest, windows-latest]
+        os: [ubuntu-latest, windows-latest, macos-latest]
         toolchain:
           - "1.85" # MSRV (Minimum supported rust version)
           - stable