Ensure that error tracking frontend only polls when required

What does this MR do?

The error tracking backend added support for the POLL-INTERVAL header in this MR: !22070 (merged).

This MR ensures that the frontend no longer bypasses that header by removing the automatic re-poll that was occurring when a 2XX response was received.

After this change, the frontend will no longer fire off polling requests many times per sec, but instead will wait for the appropriate length of time as specified by the header.

More detail in the issue: #119038 (closed).

Does this MR meet the acceptance criteria?

Conformity

• Changelog entry
• [n/a] Documentation (if required)
• Code review guidelines
• Merge request performance guidelines
• Style guides
• [n/a] Database guides
• [n/a] 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.
• [n/a] 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:

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