Remove a link to the insights page on the application header

[cakecatz]

What this PR does / why we need it:

• Remove a link to the insights page because the insights feature is not ready
  • You can access it by opening the link directly

Which issue(s) this PR fixes:

Fixes #

Does this PR introduce a user-facing change?:

Remove a link to the insights page 

[pipecd-bot]

The following ISSUES will be created once got merged. If you want me to skip creating the issue, you can use /todo skip command.

Details

---

1. Restore a link to the insights in the v1 release */}

https://github.com/pipe-cd/pipe/blob/f4ce9463ec76a72e2f716c898237f26315cd731e/pkg/app/web/src/components/header.tsx#L126-L129

This was created by todo plugin since "TODO:" was found in f4ce946 when #1256 was merged. cc: @cakecatz.

[pipecd-bot]

Code coverage for golang is 33.81%. This pull request does not change code coverage.

[pipecd-bot]

Code coverage for javascript is 81.41%. This pull request does not change code coverage.

[nghialv]

/lgtm

[khanhtc1202]

Nice 👍
/approve

[pipecd-bot]

This pull request is APPROVED by khanhtc1202.

Approvers can cancel the approval by writing /approve cancel in a comment. Any additional commits also will change this pull request to be not-approved.