Remove proposal link due to constant 429 validating it

[acroca]

At the moment we're getting lots of errors from CI validating github links, all runs getting 429.

• Removed job proposal link, as I don't think this link is so relevant, we usually don't link to proposals from examples.
• Updated CNCF code of conduct link to use their website instead of github's

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 86.89%. Comparing base (bffb749) to head (60d12de).
⚠️ Report is 87 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #947      +/-   ##
==========================================
+ Coverage   86.63%   86.89%   +0.26%     
==========================================
  Files          84      103      +19     
  Lines        4473     7305    +2832     
==========================================
+ Hits         3875     6348    +2473     
- Misses        598      957     +359     

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