Fix broken markdown links

[SylvainJuge]

Fixes few broken markdown links that prevent jobs from executing properly in CI now that markdown lint has been enabled.

The targeted file was removed in open-telemetry/opentelemetry-specification#4128.

Command to validate (copy-paste from what is executed in CI).

find . -type f \                                                                                                                                                                                                                                                                   git:(fix-broken-links)
         -name '*.md' \
         -not -path './CHANGELOG.md' \
       | xargs .github/scripts/markdown-link-check-with-retry.sh

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 90.05%. Comparing base (ad120a5) to head (f7cb38a).
Report is 3 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff            @@
##               main    #6655   +/-   ##
=========================================
  Coverage     90.05%   90.05%           
  Complexity     6275     6275           
=========================================
  Files           697      697           
  Lines         18944    18944           
  Branches       1858     1858           
=========================================
  Hits          17060    17060           
  Misses         1307     1307           
  Partials        577      577           

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[SylvainJuge]

@jack-berg since you opened the related specification PR can I let you review and merge this ? This makes other PRs like #6654 fail in CI due to this.

[jack-berg]

Thanks for the fix @SylvainJuge!