Add fixes to keep environments usage within icense limits

[nithyatsu]

Our hosting plan limits to using atmost 10 staging environments.

ref:
https://ms.portal.azure.com/#@microsoft.onmicrosoft.com/resource/subscriptions/db195b18-2f76-4384-a2fe-e4c6b39841b2/resourceGroups/docs/providers/Microsoft.Web/staticSites/radius-docs-edge/environments

https://ms.portal.azure.com/#@microsoft.onmicrosoft.com/resource/subscriptions/db195b18-2f76-4384-a2fe-e4c6b39841b2/resourceGroups/docs/providers/Microsoft.Web/staticSites/radius-docs-edge/environments

In order to not run into issues,

• We should add nightly job (or another frequency to be decided) which should delete old/unused environments.
• We should create issues when clean up / setup fails, so that the orphaned environments could be manually cleaned up
• We should provide on-call with the permissions to delete orphaned environments.
• Add a step in the beginning of the workflow to check for orphan resources and delete them as needed.

AB#13989