Add installs from wheel and source explicitly

Author: znicholls

.github/workflows/install-pypi.yaml

@@ -33,15 +33,23 @@ jobs:
           # # Only seems to be available on Mac for some reason,
           # # maybe it will be available when latest images are updated.
           # - {compiler: gcc, version: 15}
+        pip-install-flags: ["--only-binary example-fgen-basic"]
+        include:
+          # Source installs on all OS for a stable Python version
+          # (no need to do more than this)
+          - pip-install-flags: "--no-binary example-fgen-basic"
+            python-version: "3.11"
+
     runs-on: "${{ matrix.os }}"
     steps:
     - name: Set up Python "${{ matrix.python-version }}"
       id: setup-python
       uses: actions/setup-python@v4
       with:
         python-version: "${{ matrix.python-version }}"
-    # While building from source, ensure we have a Fortran compiler
     - name: Install Fortran compiler
+      # When building from source, ensure we have a Fortran compiler
+      if: matrix.pip-install-flags == '--no-binary example-fgen-basic'
       uses: fortran-lang/setup-fortran@v1
       id: setup-fortran
       with: