Resolve "Setting minimum password length breaks sign-up with SAML"

What does this MR do?

Fixes #197925 (closed)

Fixes bugs:

1. Setting minimum password length breaks when signing up with SAML/OAuth/LDAP when minimum_password_length setting was set to be anything other than 8 (the default)
2. When the minimum_password_length was set to be anything greater than 20 characters, it breaks user creation in ee/lib/ee/gitlab/scim/provisioning_service.rb and app/services/users/build_service.rb

Screenshots

Does this MR meet the acceptance criteria?

Conformity

• Changelog entry
• Documentation (if required)
• Code review guidelines
• Merge request performance guidelines
• Style guides
• Database guides
• Separation of EE specific content

Availability and Testing

• Review and add/update tests for this feature/bug. Consider all test levels. See the Test Planning Process.
• Tested in all supported browsers

Security

If this MR contains changes to processing or storing of credentials or tokens, authorization and authentication methods and other items described in the security review guidelines:

• Label as security and @ mention @gitlab-com/gl-security/appsec
• The MR includes necessary changes to maintain consistency between UI, API, email, or other methods
• Security reports checked/validated by a reviewer from the AppSec team