Skip disabled features when importing a project from Gitea

What does this MR do?

This MR is a replacement of community contribution that has been opened for over a year !16586 (closed) I took over that MR to push it to merged state, however because it's a fork I decided to create a new MR for it (since original one is 57k commits behind master) while making sure changelog mentions original contributor.

This MR rescues Octokit::NotFound exception within Gitlab::LegacyGithubImport::Importer that is used in Gitea importer (GitHub is no longer using this legacy importer) in order to not fail import and keep going when exception is occurred, since Gitea repository features such as issues, issue comments and pull requests can be disabled. In such scenario we want to track the error but continue with the import, instead of failing it.

Screenshots (strongly suggested)

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