Fix allowlist bug that prevented project access token creation

What does this MR do?

"We have several customers that are encountering an error when creating project access tokens. After further troubleshooting, it seems that they have enabled email domain whitelisting for signing up in their instance."

This MR allows instances with allow-listing enabled to create project access tokens by skipping validation on project bot creation, even if the project bot email is not on the allowed domains list.

Screenshots

Before: Attempting to create a project bot would give a 500:

  "exception.message": "First argument in form cannot contain nil or be empty",
  "exception.backtrace": [
    "app/views/shared/access_tokens/_form.html.haml:9",
    "app/views/projects/settings/access_tokens/index.html.haml:22",
    "app/controllers/application_controller.rb:134:in `render'",
    "app/controllers/projects/settings/access_tokens_controller.rb:24:in `create'",
    "ee/lib/gitlab/ip_address_state.rb:10:in `with'",
    "ee/app/controllers/ee/application_controller.rb:44:in `set_current_ip_address'",
    "app/controllers/application_controller.rb:491:in `set_current_admin'",
    "lib/gitlab/session.rb:11:in `with_session'",
    "app/controllers/application_controller.rb:482:in `set_session_storage'",
    "app/controllers/application_controller.rb:476:in `set_locale'",
    "lib/gitlab/error_tracking.rb:50:in `with_context'",
    "app/controllers/application_controller.rb:541:in `sentry_context'",
    "app/controllers/application_controller.rb:469:in `block in set_current_context'",
    "lib/gitlab/application_context.rb:52:in `block in use'",
    "lib/gitlab/application_context.rb:52:in `use'",
    "lib/gitlab/application_context.rb:20:in `with_context'",
    "app/controllers/application_controller.rb:462:in `set_current_context'",
    "ee/lib/gitlab/jira/middleware.rb:19:in `call'"
  ],

After:

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
• Informed Infrastructure department of a default or new setting change, if applicable per definition of done

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

Closes #235924 (closed)