add workflow to update flake inputs

.forgejo/workflows/nix-inputs-update.yml

@@ -0,0 +1,12 @@
+name: "Update Flake Packages ❄️"
+on:
+  workflow_dispatch:
+jobs:
+  updateFlakePackages:
+    runs-on: native
+    steps:
+      - run: git clone -q -b $FORGEJO_REF_NAME https://forgejo:$GITHUB_TOKEN@git.antoinevaure.fr/$GITHUB_REPOSITORY .
+      - run: git checkout -b update-nix-inputs
+      - run: nix flake update
+      - run: git commit -a -m "Update flake inputs $(date +'%d/%m/%Y')"
+      - run: git push --force --set-upstream origin update-nix-inputs