Upgrade web-vitals library to V5

[serchavalos]

Problem Statement

Hello! 👋

We noticed some of our LCP metrics are reported without elements and the potential fix to this issue might be already included in the version 5 of web-vitals.

For more details: GoogleChrome/web-vitals#561

Solution Brainstorm

We propose to upgrade web-vitails to v5 to see if that could fix it

[AbhiPrasad]

Hey @serchavalos - thanks for the issue. We'll need to get this done, putting it on the todo.

[Lms24]

Update:

I took a look at the changelog and it seems like it's definitely worth upgrading to get the fixes for INP, LCP and CLS.

I'm a bit worried about the removal of FID because chances are that some of our users have alerts on FID measurements that would trigger or otherwise get skewed if we also simply removed FID in our vendored version.

Which means that our vendored version will likely need to continue supporting FID in v5 (thus diverging more from the original version, as well as increasing complexity of upgrading the vendored version in the future).

I started an internal conversation if we can remove sending FID in the next SDK major (or potentially earlier). This would help reducing some of the complexity and hopefully compensate the added bundle size of v5.

Likewise, we need to evaluate if web-vitals dropping support for older browsers has influences on our browser support range. We already had to do some of this in #14439 so it's not totally unprecedented.