[docs] Cleanup canary links, use master instead

[styfle]

Follow up to #3287

[codecov-io]

Codecov Report

Merging #3291 into master will decrease coverage by 0.09%.
The diff coverage is n/a.

@@            Coverage Diff            @@
##           master    #3291     +/-   ##
=========================================
- Coverage   13.91%   13.81%   -0.1%     
=========================================
  Files         267      267             
  Lines       10297    10276     -21     
  Branches     1241     1246      +5     
=========================================
- Hits         1433     1420     -13     
+ Misses       8798     8790      -8     
  Partials       66       66

Impacted Files	Coverage Δ
src/util/prefer-v2-deployment.ts	56.25% <0%> (-5.66%)	⬇️
src/util/projects/get-project-by-id-or-name.ts	25% <0%> (-3.58%)	⬇️
src/util/metrics.ts	70.58% <0%> (+2.4%)	⬆️

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