docs: fix links to OpenTelemetry Metrics documentation

[rodrigc]

Which problem is this PR solving?

Fix broken links to OpenTelemetry Metrics documentation

Short description of the changes

Type of change

Please delete options that are not relevant.

• This change requires a documentation update

Checklist:

• Documentation has been updated

[codecov]

Codecov Report

Merging #3691 (1f250f7) into main (c4a8387) will decrease coverage by 0.97%.
The diff coverage is n/a.

❗ Current head 1f250f7 differs from pull request most recent head e38b046. Consider uploading reports for the commit e38b046 to get more accurate results

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #3691      +/-   ##
==========================================
- Coverage   93.13%   92.17%   -0.97%     
==========================================
  Files         172      145      -27     
  Lines        5461     3986    -1475     
  Branches     1182      812     -370     
==========================================
- Hits         5086     3674    -1412     
+ Misses        375      312      -63     

see 30 files with indirect coverage changes

[pichlermarc]

Thanks for updating this 🙂