update workflows (#456)

Author: itsmylife

.github/workflows/add-to-project.yml

@@ -17,7 +17,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - id: get-secrets
-        uses: grafana/shared-workflows/actions/get-vault-secrets@main
+        uses: grafana/shared-workflows/actions/get-vault-secrets@main # zizmor: ignore[unpinned-uses]
         with:
           repo_secrets: |
             GITHUB_APP_ID=grafana-oss-big-tent:app-id

.github/workflows/publish.yaml

@@ -1,5 +1,6 @@
 name: Plugins - CD
 run-name: Deploy ${{ inputs.branch }} to ${{ inputs.environment }} by @${{ github.actor }}
+permissions: {}
 
 on:
   workflow_dispatch:

.github/workflows/push.yaml

@@ -1,4 +1,5 @@
 name: Plugins - CI
+permissions: {}
 
 on:
   push: