[EXPORTERS] Remove prometheus timestamps

[carlosroman]

Fixes #2316

Changes

This returns the previous behavior from #2324 that was removed in #2213.

For significant contributions please make sure you have completed the following items:

• CHANGELOG.md updated for non-trivial changes
• Unit tests have been added
• Changes in public API reviewed

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 90.06%. Comparing base (86389bc) to head (76e70ea).
⚠️ Report is 1 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #3895   +/-   ##
=======================================
  Coverage   90.06%   90.06%           
=======================================
  Files         226      226           
  Lines        7229     7229           
=======================================
  Hits         6510     6510           
  Misses        719      719           

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[lalitb]

@carlosroman - The PR looks good, however you need to fix the failing CI tests, and merge conflicts.

[carlosroman]

@carlosroman - The PR looks good, however you need to fix the failing CI tests, and merge conflicts.

Have applied some fixes to clean up the code. I think the rest of the errors were CI infra related. Will clean up the other PR (#3894) as well in case you want to use that one instead of this one.

[lalitb]

Will clean up the other PR (#3894) as well in case you want to use that one instead of this one.

Yes, we should close #3894 in favor of this PR. Please resolve the merge conflict.

[marcalff]

I resolved the merge conflicts using the web interface, but it went poorly.

Now cleaned up manually.

[marcalff]

LGTM, to confirm in SIG meeting for merge.

[marcalff]

@lalitb To confirm, ok to merge ?