Check the doxygen version

Doxygen 1.9.7 breaks our urls, see issue #347. Let's put a check for the
doxygen version into our CI build so that if our base distro updates beyond
that, the CI fails and we know we have to build doxygen from scratch or
update to some other version that's supported.

Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>

.github/workflows/linux.yml

@@ -53,6 +53,14 @@ jobs:
           name: test logs
           path: |
             build/meson-logs/
+      - name: Ensure doxygen version is correct
+        run: |
+            doxygen --version > version.txt
+            echo "1.9.6" >> version.txt
+            if [ $(sort -V version.txt | tail -n1) != "1.9.6" ]; then
+                echo "Doxygen version 1.9.6 or earlier expected, see #347"
+                exit 1
+            fi
       - name: Store doxygen docs for use by the pages workflow
         uses: actions/upload-artifact@v3
         if: success()