Update golangci to v1.20

[kolaente]

As title.

[codecov-io]

Codecov Report

Merging #8432 into master will increase coverage by <.01%.
The diff coverage is n/a.

@@            Coverage Diff            @@
##           master   #8432      +/-   ##
=========================================
+ Coverage    41.8%   41.8%   +<.01%     
=========================================
  Files         497     497              
  Lines       65631   65631              
=========================================
+ Hits        27438   27439       +1     
+ Misses      34680   34676       -4     
- Partials     3513    3516       +3

Impacted Files	Coverage Δ
models/repo_indexer.go	68.21% <0%> (-1.94%)	⬇️
models/repo_list.go	73.17% <0%> (-0.98%)	⬇️
routers/repo/view.go	43.32% <0%> (+1%)	⬆️
modules/log/event.go	65.64% <0%> (+1.02%)	⬆️
models/unit.go	67.56% <0%> (+5.4%)	⬆️

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