feat(workflows): Switch to a nix-based definition of workflows

.forgejo/workflows/npins-update.yaml

@@ -0,0 +1,25 @@
+jobs:
+  npins_update:
+    runs-on: nix
+    steps:
+    - uses: actions/checkout@v3
+      with:
+        depth: 0
+        token: ${{ secrets.TEA_DGNUM_CHORES_TOKEN }}
+    - name: Update dependencies and open PR if necessary
+      run: "npins update\n\nif [ ! -z \"$(git diff --name-only)\" ]; then\n  echo\
+        \ \"[+] Changes detected, pushing updates.\"\n\n  git switch -C npins-update\n\
+        \n  git add npins\n\n  git config user.name \"DGNum Chores\"\n  git config\
+        \ user.email \"tech@dgnum.eu\"\n\n  git commit --message \"chore(npins): Update\"\
+        \n  git push --set-upstream origin npins-update --force\n\n  # Connect to\
+        \ the server with the cli\n  tea login add \\\n    -n dgnum-chores \\\n  \
+        \  -t \"${{ secrets.TEA_DGNUM_CHORES_TOKEN }}\" \\\n    -u https://git.dgnum.eu\n\
+        \n  # Create a pull request if needed\n  # i.e. no PR with the same title\
+        \ exists\n  if [ -z \"$(tea pr ls -f='title,author' -o simple | grep 'chore(npins):\
+        \ Update dgnum-chores')\" ]; then\n    tea pr create \\\n      --description\
+        \ \"Automatic npins update\" \\\n      --title \"chore(npins): Update\" \\\
+        \n      --head npins-update\n  fi\nfi\n"
+name: npins update
+'on':
+  schedule:
+  - cron: 25 15 * * *