Use Node 14 on CI

[silverwind]

Node 14 is sufficiently stable now, use it on CI. Also switched the build step to it as I think it makes more sense to run the build on the same version the dependencies were installed for, even if we're missing out a validation by running the old version.

[codecov-commenter]

Codecov Report

Merging #12512 into master will decrease coverage by 0.02%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master   #12512      +/-   ##
==========================================
- Coverage   43.54%   43.52%   -0.03%     
==========================================
  Files         637      637              
  Lines       70825    70825              
==========================================
- Hits        30844    30829      -15     
- Misses      34978    34992      +14     
- Partials     5003     5004       +1     

Impacted Files	Coverage Δ
models/repo_mirror.go	2.38% <0.00%> (-11.91%)	⬇️
modules/cron/tasks_basic.go	87.35% <0.00%> (-3.45%)	⬇️
modules/git/utils.go	73.77% <0.00%> (-3.28%)	⬇️
modules/queue/workerpool.go	58.77% <0.00%> (-3.27%)	⬇️
services/pull/check.go	47.69% <0.00%> (-2.31%)	⬇️
services/mirror/mirror.go	18.21% <0.00%> (-1.49%)	⬇️
models/error.go	34.81% <0.00%> (-0.52%)	⬇️
modules/git/repo.go	49.23% <0.00%> (-0.51%)	⬇️
models/issue_comment.go	53.75% <0.00%> (-0.16%)	⬇️
routers/repo/view.go	37.98% <0.00%> (+0.64%)	⬆️
... and 5 more

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[techknowlogick]

Can you bump makefile to have node 12 as minimum node version? Also update docs?

[silverwind]

The minimum version will stay at 10.13 for now, this just raises the version used on CI.

It does change the build step because I think it makes more sense to install dependencies and build on the same version and 14 also brings some performance improvements over 10. We lose the verification that it still builds on 10 this way but I don't think doing another 6-minute build is justified for it.

[techknowlogick]

🚀