Update actions and pre-commit checks to match other repos

This groups Dpendabot updates and tiggers `prek auto-update` when Dependabot
uppdates GitHub actions.

Author: danielparks

.github/dependabot.yml

@@ -5,3 +5,19 @@ updates:
     directory: "/"
     schedule:
       interval: "monthly"
+    groups:
+      github-actions:
+        patterns:
+          - "*"
+
+  - package-ecosystem: "cargo"
+    directory: "/"
+    schedule:
+      interval: "monthly"
+    # Security updates only:
+    open-pull-requests-limit: 0
+    groups:
+      cargo-dependencies:
+        applies-to: security-updates
+        patterns:
+          - "*"

.github/workflows/dependabot-prek.yaml

@@ -0,0 +1,34 @@
+name: Dependabot `prek auto-update`
+
+on:
+  push:
+    branches:
+      - "dependabot/github_actions/**"
+
+jobs:
+  prek-auto-update:
+    # Only run on dependabot PRs
+    if: github.actor == 'dependabot[bot]'
+    runs-on: ubuntu-latest
+    permissions:
+      contents: write
+    steps:
+      - uses: actions/checkout@v6
+        with:
+          ref: ${{ github.head_ref }}
+          token: ${{ secrets.PUSH_TOKEN }}
+      - uses: taiki-e/install-action@v2
+        with:
+          tool: prek
+      - run: prek auto-update
+
+      - name: Commit changes
+        run: |
+          git config user.name "github-actions[bot]"
+          git config user.email "41898282+github-actions[bot]@users.noreply.github.com"
+
+          if [[ -n $(git status --porcelain) ]]; then
+            git add -A
+            git commit -m $'`prek auto-update`\n\n[dependabot skip]'
+            git push
+          fi

.pre-commit-config.yaml

@@ -17,14 +17,14 @@ repos:
       - id: detect-private-key
       - id: mixed-line-ending
         args: ["--fix=no"]
-        exclude: "^target/"
+        exclude: "target/"
       - id: no-commit-to-branch
   - repo: https://github.com/crate-ci/typos
     rev: v1.41.0
     hooks:
       - id: typos
         args: []
-        exclude: "^target/"
+        exclude: "target/"
   - repo: local
     hooks:
       - id: cargo clippy