Un-quarantine import project using instance template spec

What does this MR do?

1. Un-quarantine import project using instance template spec
2. Skips the test in staging due to #228624 (closed)
3. retry_until the newly added instance template is shown on project creation UI.

Related to #13418 (closed)

Conformity

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

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