Improve browsers support

[maciaszczykm]

What this PR does / why we need it:

Which issue(s) this PR fixes (optional, in fixes #<issue number>(, fixes #<issue_number>, ...) format, will close the issue(s) when PR gets merged):
Fixes #2660

Special notes for your reviewer:

➜ browserslist
and_chr 85
and_ff 79
chrome 85
chrome 84
edge 85
edge 84
firefox 81
firefox 80
ios_saf 14.0
ios_saf 13.4-13.7
safari 14
safari 13.1

➜ browserslist --coverage       
These browsers account for 72% of all users globally

Release note:

Improve browsers support.

[kubermatic-bot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: maciaszczykm

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• OWNERS [maciaszczykm]

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[kubermatic-bot]

Skipping CI for Draft Pull Request.
If you want CI signal for your change, please convert it to an actual PR.
You can still manually trigger a test run with /test all

[maciaszczykm]

I've added an issue for the core repo: kubermatic/kubermatic#5958

[maciaszczykm]

/assign @kgroschoff @floreks

[codecov]

Codecov Report

Merging #2668 into master will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master    #2668   +/-   ##
=======================================
  Coverage   52.42%   52.42%           
=======================================
  Files         234      234           
  Lines        8213     8213           
  Branches      990      990           
=======================================
  Hits         4306     4306           
  Misses       3904     3904           
  Partials        3        3           

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[floreks]

/lgtm

[kubermatic-bot]

LGTM label has been added.

Git tree hash: 7d19d73df282936671520c72b26c5407608c49c5