Update GitHub Actions workflows. (#240)

This PR was automatically generated by the
update-native-provider-workflows workflow in the pulumi/ci-mgmt repo,
from commit 1ade282c11c4b1e46d1ede6d849c8972f0e2f4e2.

.github/workflows/weekly-pulumi-update.yml

@@ -127,12 +127,10 @@ jobs:
     - name: Create PR
       id: create-pr
       if: steps.gomod.outputs.changes != 0
-      uses: repo-sync/pull-request@v2.6.2
-      with:
-        source_branch: update-pulumi/${{ github.run_id }}-${{ github.run_number }}
-        destination_branch: main
-        pr_title: Automated Pulumi/Pulumi upgrade
-        github_token: ${{ secrets.PULUMI_BOT_TOKEN }}
+      run: |
+        ver=$(cat .pulumi.version)
+        msg="Automated upgrade: bump pulumi/pulumi to ${ver}"
+        gh pr create -t "$msg" -b "$msg" -B main
       env:
         GITHUB_TOKEN: ${{ secrets.PULUMI_BOT_TOKEN }}
     name: weekly-pulumi-update