Temporarily disable broken demos in CI.

.github/workflows/ci.yml

@@ -30,6 +30,14 @@ jobs:
           sudo apt-get update
           sudo apt-get install make chocolate-doom python3 python3-yaml
 
+      - name: Patch out broken demos
+        run: |
+          # These work in Chocolate Doom HEAD but don't seem to currently
+          # work in the older version in ubuntu-latest.
+          # TODO: Reenable these.
+          grep -v 30av-25337 < demos.txt | grep -v pl2all1.txt > new-demos.txt
+          mv new-demos.txt demos.txt
+
       - name: Run checks
         run: |
           make check