Fix CI: Create a Python venv (#371)

.github/workflows/compile.yml

@@ -2,7 +2,7 @@ name: compilepaper
 on: [push, pull_request]
 jobs:
   paper:
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-24.04
     env:
       DIR: .
     steps:
@@ -19,7 +19,10 @@ jobs:
             texlive-fonts-recommended texlive-fonts-extra lmodern fonts-linuxlibertine \
             python3 python3-yaml \
             xz-utils make sed gpg-agent
+          python3 -m venv ${{ env.DIR }}/venv && source ${{ env.DIR }}/venv/bin/activate
           python3 -m pip install -r ${{ env.DIR }}/requirements.txt
+          # Workaround for https://github.com/tomduck/pandoc-xnos/pull/29
+          python3 -m pip install --force-reinstall git+https://github.com/tomduck/pandoc-xnos@284474574f51888be75603e7d1df667a0890504d#egg=pandoc-xnos
       - name: Fetch bibliography
         run : |
           # resolve relative paths in forked projects
@@ -28,7 +31,7 @@ jobs:
           git config --local submodule.recurse true
       - name: pandoc compile
         working-directory: ${{ env.DIR }}
-        run: make all
+        run: source ${{ env.DIR }}/venv/bin/activate && make all
       - name: move
         run: mkdir -p github_artifacts && mv ${{ env.DIR }}/*.pdf ./github_artifacts/
       - name: Upload pdf as artifact