CI: Open PR for pending SQL promotion

.github/workflows/promote-pending-sql.yml

@@ -9,6 +9,7 @@ on:
 
 permissions:
   contents: write
+  pull-requests: write
 
 concurrency:
   group: ${{ github.workflow }}-${{ github.ref }}
@@ -29,9 +30,14 @@ jobs:
         shell: pwsh
         run: ./tools/dev/promote_pending_updates.ps1 -Apply
 
-      - name: Commit promoted SQL updates
+      - name: Open promoted SQL pull request
         shell: pwsh
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
         run: |
+          $branchName = "automation/promote-pending-sql-${{ github.run_id }}"
+
+          git switch -c $branchName
           git add -A sql/pending_updates sql/updates
 
           $changes = git status --porcelain
@@ -46,4 +52,23 @@ jobs:
           git config user.name "github-actions[bot]"
           git config user.email "41898282+github-actions[bot]@users.noreply.github.com"
           git commit -m "SQL: Promote pending updates"
-          git push origin HEAD:${{ github.ref_name }}
+          git push origin HEAD:refs/heads/$branchName
+
+          $headers = @{
+            Authorization = "Bearer $env:GITHUB_TOKEN"
+            Accept = "application/vnd.github+json"
+            "X-GitHub-Api-Version" = "2022-11-28"
+          }
+          $body = @{
+            title = "SQL: Promote pending updates"
+            head = $branchName
+            base = "${{ github.ref_name }}"
+            body = "Automated promotion from sql/pending_updates into sql/updates."
+          } | ConvertTo-Json
+
+          Invoke-RestMethod `
+            -Method Post `
+            -Uri "https://api.github.com/repos/${{ github.repository }}/pulls" `
+            -Headers $headers `
+            -Body $body `
+            -ContentType "application/json"