Revert "overhauled workflow"

This reverts commit 0d41c66fccb051a5c17f1f7f036299f4e8a88080.

.github/workflows/update.yml

@@ -1,6 +1,6 @@
-name: Update `flake.lock`
+name: update-flake-lock
 on:
-  workflow_dispatch:
+  workflow_dispatch: # allows manual triggering
   schedule:
     - cron: "0 0 * * 0" # runs weekly on Sunday at 00:00
 
@@ -10,75 +10,13 @@ jobs:
     steps:
       - name: Checkout repository
         uses: actions/checkout@v4
-      - name: Install nix
-        uses: https://github.com/DeterminateSystems/nix-installer-action@main
-      - name: Setup Action cache for nix
-        uses: https://github.com/DeterminateSystems/magic-nix-cache-action@main
-
+      - name: Install Nix
+        uses: DeterminateSystems/nix-installer-action@main
       - name: Update flake.lock
-        id: update
-        run: |
-          nix flake update 2> >(tee /dev/stderr) | awk '
-            /^• Updated input/ {in_update = 1; print; next}
-            in_update && !/^warning:/ {print}
-            /^$/ {in_update = 0}
-          ' > update.log
-
-          echo "UPDATE_LOG<<EOF" >> $GITHUB_ENV
-          cat update.log >> $GITHUB_ENV 
-          echo "EOF" >> $GITHUB_ENV
-
-          rm update.log
-
-      - name: Write PR body template
-        uses: https://github.com/DamianReeves/write-file-action@v1.3
-        with:
-          path: pr_body.template
-          contents: |
-            - The following Nix Flake inputs were updated:
-
-            ```
-            ${{ env.UPDATE_LOG }}
-            ```
-
-            Auto-generated by [update.yml][1] with the help of
-            [create-pull-request][2].
-
-            [1]: https://forgejo.stefka.eu/jiriks74/nix.nvim/src/branch/main/.github/workflows/update.yml
-            [2]: https://forgejo.stefka.eu/jiriks74/create-pull-request
-
-      - name: Generate PR body
-        uses: pedrolamas/handlebars-action@v2.4.0 # v2.4.0
-        with:
-          files: "pr_body.template"
-          output-filename: "pr_body.md"
-      - name: Save PR body
-        id: pr_body
-        uses: juliangruber/read-file-action@v1
-        with:
-          path: "pr_body.md"
-
-      - name: Remove temporary files
-        run: |
-          rm pr_body.template
-          rm pr_body.md
-
-      - name: Create Pull Request
-        id: create-pull-request
-        uses: https://forgejo.stefka.eu/jiriks74/create-pull-request@2c60f3517609825873003cde0d4367c6cc2cd74c
+        uses: DeterminateSystems/update-flake-lock@main
         with:
+          pr-title: "Update flake.lock" # Title of PR to be created
+          pr-labels: | # Labels to be set on the PR
+            dependencies
+            automated
           token: ${{ secrets.GH_TOKEN }}
-          body: ${{ steps.pr_body.outputs.content }}
-          author: '"github-actions[bot]" <github-actions[bot]@users.noreply.github.com>'
-          title: "automated: Update `flake.lock`"
-          commit-message: |
-            automated: Update `flake.lock`
-
-            ${{ steps.pr_body.outputs.content }}
-
-          branch: update-flake-lock
-          delete-branch: true
-      - name: Print PR number
-        run: |
-          echo "Pull request number is ${{ steps.create-pull-request.outputs.pull-request-number }}."
-          echo "Pull Request URL - ${{ steps.cpr.outputs.pull-request-url }}"   options