Bug 1932096 - Create a GitHub action cron job to periodiaclly update in-tree data dumps

We want to keep the in-tree remote-settings dumps up to date. For this, a GitHub Actions workflow
seems to be the easiest way for now. The workflow will check once a week if there is new data (through
the `cargo remote-settings dump-sync` command). And commit any changes to a new branch and open a PR
against main.

.github/workflows/update-remote-settings-dumps.yaml

@@ -0,0 +1,63 @@
+name: Update Remote Settings Dumps
+
+on:
+  schedule:
+    - cron: "0 0 * * 0" # Run weekly on Sunday at midnight
+  workflow_dispatch: # Allow manual trigger
+    inputs:
+      base_branch:
+        description: 'Base branch'
+        required: true
+        default: 'main'
+
+jobs:
+  update-dumps:
+    runs-on: ubuntu-latest
+    permissions:
+      contents: write
+      pull-requests: write
+
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+        with:
+          ref: main
+          fetch-depth: 0
+          submodules: recursive
+
+      - name: Set up repository and install Rust
+        run: |
+          curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh -s -- -y
+          source $HOME/.cargo/env
+
+      - name: Create new branch and run dump
+        run: |
+          # Configure git
+          git config --local user.email "bgruber@mozilla.com"
+          git config --local user.name "Bastian Gruber"
+          
+          # Create new branch
+          BRANCH_NAME="update-remote-settings-dumps-$(date +%Y%m%d)"
+          git checkout -b $BRANCH_NAME
+          
+          # Run the dump command
+          cargo remote-settings dump-sync
+          
+          # Check for changes and create PR if needed
+          git add ./components/remote_settings/dumps/
+          if git status --porcelain -- ./components/remote_settings/dumps/ | grep .; then
+            git commit -m "chore: Update remote settings dumps"
+            git push origin $BRANCH_NAME
+          
+            # Create the PR (gh is installed on GH Actions)
+            gh pr create \
+              --title "Update Remote Settings Dumps" \
+              --body "Automated PR to update remote settings dumps.
+
+              Changes detected in: \`./components/remote_settings/dumps/\`
+              Generated by the Update Remote Settings Dumps workflow." \
+              --base main \
+              --head $BRANCH_NAME
+          else
+            echo "No changes detected in dumps directory"
+          fi