Issue Summary

This is reproducible on Data Center: yes

Steps to Reproduce

1. Create a plan in JCMA or CCMA with apps that have an automated migration path
2. Start migration 
3. Remove your use from site admins in target cloud site
4. JCMA or CCMA will start throwing 403s and app migration fails

Expected Results

JCMA and CCMA can gracefully handle scenarios when users temporarily lose site admin access

Actual Results

App migration hard fails. Example logs in this scenario

com.atlassian.jira.migration.httpclient.exceptions.UnexpectedStatusCodeException: Received an unexpected status code; expected [200], but received 403: {"timestamp":"Feb 13, 2025, 7:01:30PM","status":403,"error":"Forbidden","path":"/api/migration/upload/url"}
at com.atlassian.jira.migration.httpclient.exceptions.ExceptionsKt.unexpectedStatusCode(Exceptions.kt:9)
at 

Workaround

Ensure there are no automation rules that may temporarily remove site admin access for the user performing the migration