Deleted Entra groups remain referenced in group role assignments and MCP access policies

[sangee2004]

Describe the bug
After an Entra group is deleted and group synchronization completes, access associated with that group is correctly revoked from its users. However, the deleted group continues to appear in existing Group Role Assignments and MCP Access Policies, leaving stale and confusing references in the UI. The corresponding group role assignment should be removed, and the deleted group should also be removed from any MCP access policies that reference it.

Pre-req - Have the Entra provider configured. Delete the default MCP Access Policies that provide MCP server access to all users.

To Reproduce
Steps to reproduce the behavior:

1. Log in as admin and create a Group Role Assignment for any group, say - test1, with assigned role as "Admin"
2. Create an MCP access policy for a group, say - test1, and assign a few MCP servers to this group.
3. Log in as any user that belongs to group test1
   The user will be provided with admin access and access to MCP servers from the MCP access policy created in step 2.
4. Delete the group test1 from Entra

Wait 15-20 minutes for the group sync to complete.

Notice that the Group Role Assignment created in step 1 continues to be present and associated with the deleted group.
MCP access policy created in step 2 continues to have the deleted group

The group deletion itself takes effect. The user loses access to the group role assignment/access policy they were granted because of the group assignment, as expected. But Group Role Assignment and MCP access policy continue to have references to the deleted group, which is confusing.

Expected behavior
Group Role Assignment created in step 1 should be deleted.
MCP access policy created in step2 should not show the deleted group anymore.