Disable ETag caching on notes due to issues with pagination

What does this MR do?

We've noticed that this conditional ETag caching doesn't work as expected due to how ETag is handled currently. It would require more rework to make this conditional ETag working, but we can disable ETag caching for now as we believe pagination would improve the performance.

I think that'll give us quicker feedback about the effectiveness of pagination and we can decide if we need to look into ETag again for this endpoint.

Related to #209784 (closed) and !52089 (comment 489723230)

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

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• 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
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