Upgrade golangci-lint

[lrahmani]

Proposed changes

[codecov-commenter]

Codecov Report

Merging #1490 into develop will decrease coverage by 0.01%.
The diff coverage is n/a.

@@             Coverage Diff             @@
##           develop    #1490      +/-   ##
===========================================
- Coverage    88.76%   88.74%   -0.02%     
===========================================
  Files          243      243              
  Lines        17178    17178              
===========================================
- Hits         15248    15245       -3     
- Misses        1930     1933       +3     

Flag	Coverage Δ
#unittests	88.74% <ø> (-0.02%)	⬇️

Impacted Files	Coverage Δ
aea/test_tools/test_cases.py	85.22% <0.00%> (-1.71%)	⬇️
aea/mail/base.py	100.00% <0.00%> (+1.78%)	⬆️

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[DavidMinarsch]

LGTM