Directly PR milestone updates

.github/workflows/trigger-updates.yaml

@@ -6,16 +6,38 @@ on:
       - master
 
 jobs:
-  generate:
+  update-docs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
         repo: [lsst-dm/dmtn-158]
     steps:
-      - name: Trigger ${{ matrix.repo }} update
+      - uses: actions/checkout@v2
+        with:
+          token: ${{ secrets.ROBO_JDS_PAT }}
+          repository: ${{ matrix.repo }}
+          fetch-depth: 0
+          submodules: true
+
+      - name: Update milestones submodule
+        run: git submodule update --remote --force milestones
+
+      - name: Create commit
         run: |
-          curl --request POST \
-          --header "Accept: application/vnd.github.v3+json" \
-          --data '{"ref": "master"}' \
-          --header 'authorization: Bearer ${{ secrets.DOC_UPDATE }}' \
-          https://api.github.com/repos/${{ matrix.repo }}/actions/workflows/update-milestones.yaml/dispatches
+          git config user.name github-actions
+          git config user.email github-actions@github.com
+          git add milestones
+          git commit -m "Update milestones submodule"
+
+      - name: Get date
+        id: get-date
+        run: echo "::set-output name=date::$(/bin/date -u "+%Y-%m-%d %H:%M:%S")"
+        shell: bash
+
+      - name: Create Pull Request
+        uses: peter-evans/create-pull-request@v3
+        with:
+          token: ${{ secrets.ROBO_JDS_PAT }}
+          branch: update-milestones
+          branch-suffix: timestamp
+          title: Automatic milestone submodule update, ${{ steps.get-date.outputs.date }}