handle emu idp group 404 (#2385)

Co-authored-by: Corey Lane <corey.lane@orion.com>

Author: coreylane

github/resource_github_emu_group_mapping.go

@@ -85,6 +85,11 @@ func resourceGithubEMUGroupMappingRead(d *schema.ResourceData, meta interface{})
 
 	group, resp, err := client.Teams.GetExternalGroup(ctx, orgName, id64)
 	if err != nil {
+		if resp != nil && resp.StatusCode == 404 {
+			// If the group is not found, remove it from state
+			d.SetId("")
+			return nil
+		}
 		return err
 	}