Fix password history policy failure

[Nkwenti-Severian-Ndongtsop]

What this PR does / why we need it:

This PR improves the user import process by gracefully handling password policy violations (e.g. password history limits) during user updates.

When Keycloak returns a password policy violation, the import now retries the update without the password, allowing the remaining user attributes to be updated successfully instead of failing the entire import.

Which issue this PR fixes

fixes #1112

Special notes for your reviewer:

• The retry logic only applies to password policy violations; other 400 errors are re-thrown immediately
• Non-password fields (email, firstName, lastName, etc.) are preserved during the retry
• Unit testscover
  • The retry path when a password policy violation occurs
  • The normal path when the update succeeds without errors
• This PR completes and supersedes the work originally started in branch

PR Readiness Checklist:

• the CHANGELOG.md release notes have been updated to reflect any significant (and particularly user-facing) changes introduced by this PR

[sonarqubecloud]

Quality Gate passed

Issues
3 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud