fix(docs): broken link for community contribution lifecycle and processes

[trivikr]

Which problem is this PR solving?

• Fixes broken links missed in fix(docs): broken link for community contribution lifecycle and processes #2542

Short description of the changes

• Fixes the broken link for contribution processes which were moved in Add skeleton for maintainer and contributor guidebooks community#2051
• Verified that there are no more occurrences

Before

$ grep -rnI 'community/blob/[^/]*/CONTRIBUTING.md' .
./CONTRIBUTING.md:91:Please also see [GitHub workflow](https://github.com/open-telemetry/community/blob/main/CONTRIBUTING.md#github-workflow) section of general project contributing guide.
./.github/PULL_REQUEST_TEMPLATE.md:10:  - See https://github.com/open-telemetry/community/blob/main/CONTRIBUTING.md#sign-the-cla

After

$ grep -rnI 'community/blob/[^/]*/CONTRIBUTING.md' .

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 90.80%. Comparing base (bf8117e) to head (17296c5).
Report is 1 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #2576      +/-   ##
==========================================
+ Coverage   90.75%   90.80%   +0.04%     
==========================================
  Files         169      169              
  Lines        8018     8018              
  Branches     1632     1632              
==========================================
+ Hits         7277     7281       +4     
+ Misses        741      737       -4     

see 1 file with indirect coverage changes

[pichlermarc]

thanks 👍