Replace hardcoded grafana url with actions secret

.github/workflows/branch-deploy.yaml

@@ -275,14 +275,15 @@ jobs:
                   },
                   {
                     "type": "mrkdwn",
-                    "text": "*Logs:*\n<https://${{ secrets.STAGING_GRAFANA_URL }}/explore?orgId=1&left=%7B%22datasource%22:%22P8E80F9AEF21F6940%22,%22queries%22:%5B%7B%22refId%22:%22A%22,%22editorMode%22:%22code%22,%22expr%22:%22%7Bnamespace%3D%5C%22pr-${{ env.PR_NUMBER }}%5C%22%7D%20%7C%3D%20%60%60%20%7C%20json%22,%22queryType%22:%22range%22%7D%5D,%22range%22:%7B%22from%22:%22now-30m%22,%22to%22:%22now%22%7D%7D|View>"
+                    "text": "*Logs:*\n<https://${{ env.GRAFANA_URL }}/explore?orgId=1&left=%7B%22datasource%22:%22P8E80F9AEF21F6940%22,%22queries%22:%5B%7B%22refId%22:%22A%22,%22editorMode%22:%22code%22,%22expr%22:%22%7Bnamespace%3D%5C%22pr-${{ env.PR_NUMBER }}%5C%22%7D%20%7C%3D%20%60%60%20%7C%20json%22,%22queryType%22:%22range%22%7D%5D,%22range%22:%7B%22from%22:%22now-30m%22,%22to%22:%22now%22%7D%7D|View>"
                   }
                 ]
               }
             ]
           }
       env:
         SLACK_BOT_TOKEN: ${{ secrets.SLACK_GHBOT_TOKEN }}
+        GRAFANA_URL: ${{ secrets.STAGING_GRAFANA_URL }}
 
 
   destroy: