feat(ci): setup update-flakes workflow

.github/workflows/update-flakes.yml

@@ -0,0 +1,31 @@
+---
+name: update-flakes
+
+on:
+  workflow_dispatch: # allows manual triggering
+
+jobs:
+  lockfile:
+    runs-on: ubuntu-latest
+    steps:
+      - name: checkout repository
+        uses: actions/[email protected]
+
+      - name: install Nix
+        uses: cachix/install-nix-action@6a9a9e84a173d90b3ffb42c5ddaf9ea033fad011 # v23
+        with:
+          extra_nix_config: |
+            access-tokens = github.com=${{ secrets.GITHUB_TOKEN }}
+
+      - name: update flake.lock
+        id: update
+        uses: DeterminateSystems/update-flake-lock@v20
+        with:
+          token: ${{ secrets.NIX_FLAKES_UPDATE_TOKEN }}
+          pr-title: "chore(flake): update flake.lock"
+          commit-msg: "chore(flake): update flake.lock"
+          branch: "update_flake"
+          git-author-name: "JesusMtnez[bot]"
+          git-author-email: "github-actions[bot]@users.noreply.github.com"
+          git-committer-name: "JesusMtnez[bot]"
+          git-committer-email: "github-actions[bot]@users.noreply.github.com"