Teams page incorrectly marks memberships as managed by identity provider and disallows management

### Environment SaaS (https://sentry.io/) ### Steps to Reproduce I'm a little unclear on exactly what's causing this issue, but our account is managed with a saml provider with a single team managed by it. All other team memberships are managed with the [Sentry terraform provider](https://github.com/jianyuan/terraform-provider-sentry). Our terraform team mapping doesn't seem capable of deleting memberships, hence why we look to the team page to remove members. This issue only seems to effect teams managed with this terraform provider. 1. Create team in Terraform 2. Locate the member's member ID from the organization member mapping 3. Create the team membership mapping with the `sentry_team_member` resource 4. View the team under `/settings/teams/` and look for the membership ### Expected Result When viewing the team on the `/settings/teams/` page, teams memberships created with Terraform should be removable. Only teams managed by the identity provider should have unremovalable members. ### Actual Result Team memberships created with the method described listed on team `/settings/teams/` page have grayed out remove button indicating that the team member cannot be removed as it is managed by the identity provider. This issue seems to be an issue with the teams page in particular, as the team can be removed from the `/settings/members/` page (with the exception of the actual identity provider managed team). <img width="319" alt="Screenshot 2024-06-03 at 18 12 20" src="https://github.com/getsentry/sentry/assets/696064/288d024c-1b1c-4f6a-85e9-cc4726fbdb1c"> ### Product Area Settings - Teams ### Link _No response_ ### DSN _No response_ ### Version _No response_ ┆Issue is synchronized with this [Jira Improvement](https://getsentry.atlassian.net/browse/FEEDBACK-2190) by [Unito](https://www.unito.io)