Add add-to-project step & rename workflow assign-issue workflow file

We are updating the workflows to auto-add new issues & PR to actions/cache project board.

.github/workflows/issue-opened-workflow.yml

@@ -0,0 +1,22 @@
+name: Assign issue
+on:
+  issues:
+    types: [opened]
+jobs:
+  run-action:
+    runs-on: ubuntu-latest
+    steps:
+    - name: Get current oncall
+      id: oncall
+      run: |
+        echo "CURRENT=$(curl --request GET 'https://api.pagerduty.com/oncalls?include[]=users&schedule_ids[]=P5VG2BX&earliest=true' --header 'Authorization: Token token=${{ secrets.PAGERDUTY_TOKEN }}' --header 'Accept: application/vnd.pagerduty+json;version=2' --header 'Content-Type: application/json' | jq -r '.oncalls[].user.name')" >> $GITHUB_OUTPUT
+    
+    - name: add_assignees
+      run: |
+        curl -X POST -H "Accept: application/vnd.github+json" -H "Authorization: Bearer ${{ secrets.GITHUB_TOKEN}}" https://api.github.com/repos/${{github.repository}}/issues/${{ github.event.issue.number}}/assignees -d '{"assignees":["${{steps.oncall.outputs.CURRENT}}"]}'
+
+    - uses: actions/add-to-project@v0.4.0
+      name: Add to Project Board
+      with:
+        project-url: https://github.com/orgs/actions/projects/12                       
+        github-token: ${{ secrets.CACHE_BOARD_TOKEN }}