Azure SCIM user sync/delete error

### Environment

self-hosted (https://develop.sentry.dev/self-hosted/)

### Steps to Reproduce

1. Configure Azure SSO and SCIM based on https://docs.sentry.io/organization/authentication/sso/azure-sso/#scim-integration
2. Add or remove a user in Azure to Enterprise Application > Users and Groups
3. SCIM runs automatically every 40 minutes

### Expected Result

1. User is added/updated or removed based on if he is present in Enterprise Application > Users and Groups

### Actual Result

When adding user to Users and Groups in Enterprise application, SCIM successfully creates user on initial run.

Each subsequent SCIM runs produce error for every user:

**Failure**
Action: Update
UPN : xxxxxx
Type: `urn:ietf:params:scim:schemas:extension:enterprise:2.0:User`

**Details**
Error code: `SystemForCrossDomainIdentityManagementServiceIncompatible`

StatusCode: BadRequest
Message: Processing of the HTTP request resulted in an exception. Please see the HTTP response returned by the 'Response' property of this exception for details.
Web Response:
```
{
"schemas": ["urn:ietf:params:scim:api:messages:2.0:Error"],
"detail": {
"Operations": {
"op": ["\"add\" is not a valid choice"],
"value": ["value must be a boolean or object"]
}
}
}
```
I came across similar issue in a different thread: https://github.com/getsentry/sentry/issues/79354, where OP suggested:
"Update: the original reported solved the issue by removing the "update" option from "Target Object Actions" in Azure."

It does resolve the issue with subsequent SCIM runs and the user creation works, however, user removal does not work.

### Product Area

Settings - Auth

### Link

_No response_

### DSN

_No response_

### Version

25.1.0

Start with the Azure SSO and SCIM integration documentation linked in the report, then trace the self-hosted authentication entry point handling SCIM user updates and removals. Reproduce the scheduled add, update, and delete operations against Azure, and consider the issue done when all three complete without the reported BadRequest response.

Written by the indexing model from the issue text.