ci: add cert-update cron workflow

.github/workflows/cert-update.yml

@@ -0,0 +1,47 @@
+on:
+  workflow_dispatch:
+  schedule:
+    # Run on wednesdays at 12:10 UTC
+    - cron:  '10 12 * * 3'
+
+name: cert-update
+permissions:
+  contents: read
+
+jobs:
+  test-cert-update:
+    name: Update test certificates
+    runs-on: ubuntu-latest
+    permissions:
+      contents: write
+      pull-requests: write
+    steps:
+      - name: Check out code
+        uses: actions/checkout@v3
+        with:
+          persist-credentials: false
+
+      # Note: presently need Rust nightly to use the Cargo scripting feature.
+      - name: Install Rust nightly
+        uses: dtolnay/rust-toolchain@nightly
+
+      - name: Run update script
+        run: src/tests/verification_real_world/update_valid_ee_certs.rs
+
+      - name: Create pull-request
+        id: cpr
+        uses: peter-evans/create-pull-request@v4
+        with:
+          commit-message: "tests: update verification_real_world test certificates"
+          title: "tests: update verification_real_world test certificates"
+          body: ":robot: This PR was automatically generated by the cert-update workflow."
+          committer: "GitHub <[email protected]>"
+          author: "GitHub <[email protected]>"
+          branch: test-cert-update
+          branch-suffix: timestamp
+          delete-branch: true
+
+      - name: Check outputs
+        run: |
+          echo "Pull Request Number - ${{ steps.cpr.outputs.pull-request-number }}"
+          echo "Pull Request URL - ${{ steps.cpr.outputs.pull-request-url }}"