feat: trigger Sourcebot sync after Zoekt merges

.github/workflows/sync-sourcebot.yml

@@ -0,0 +1,58 @@
+name: Sync Sourcebot Zoekt Dependency
+
+# This workflow needs base-repository secrets for the cross-repository dispatch.
+# It never checks out or executes pull request code.
+on:
+  pull_request_target:
+    types: [closed]
+
+permissions:
+  contents: read
+
+jobs:
+  dispatch:
+    if: >-
+      github.event.pull_request.merged == true &&
+      github.event.pull_request.base.ref == github.event.repository.default_branch
+    runs-on: ubuntu-latest
+    steps:
+      - name: Generate Sourcebot GitHub App token
+        id: app-token
+        uses: actions/create-github-app-token@v2
+        with:
+          app-id: ${{ secrets.SOURCEBOT_SYNC_APP_ID }}
+          private-key: ${{ secrets.SOURCEBOT_SYNC_APP_PRIVATE_KEY }}
+          owner: sourcebot-dev
+          repositories: sourcebot
+          permission-contents: write
+
+      - name: Request Sourcebot dependency update
+        env:
+          GH_TOKEN: ${{ steps.app-token.outputs.token }}
+          ZOEKT_SHA: ${{ github.event.pull_request.merge_commit_sha }}
+          ZOEKT_PR_NUMBER: ${{ github.event.pull_request.number }}
+        run: |
+          set -euo pipefail
+
+          jq -n \
+            --arg zoekt_sha "$ZOEKT_SHA" \
+            --arg zoekt_pr_number "$ZOEKT_PR_NUMBER" \
+            '{
+              event_type: "zoekt-pr-merged",
+              client_payload: {
+                zoekt_sha: $zoekt_sha,
+                zoekt_pr_number: $zoekt_pr_number
+              }
+            }' \
+            | gh api \
+                --method POST \
+                --header "Accept: application/vnd.github+json" \
+                --header "X-GitHub-Api-Version: 2022-11-28" \
+                --input - \
+                repos/sourcebot-dev/sourcebot/dispatches
+
+          {
+            echo "## Sourcebot sync requested"
+            echo
+            echo "Dispatched Zoekt PR #$ZOEKT_PR_NUMBER at \`$ZOEKT_SHA\`."
+          } >> "$GITHUB_STEP_SUMMARY"