use cobra default auto completion

[nexustar]

What problem does this PR solve?

cobra support auto completion command since 1.2 https://github.com/spf13/cobra/releases/tag/v1.2.0

What is changed and how it works?

use cobra build-in auto completion

Check List

Tests

• Unit test
• Integration test
• Manual test (add detailed scripts or steps below)
• No code

Release notes:

NONE

[ti-chi-bot]

[REVIEW NOTIFICATION]

This pull request has been approved by:

• AstroProfundis

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[codecov-commenter]

Codecov Report

Merging #1549 (6bce0c7) into master (551e758) will increase coverage by 26.77%.
The diff coverage is n/a.

❗ Current head 6bce0c7 differs from pull request most recent head 2e859b0. Consider uploading reports for the commit 2e859b0 to get more accurate results

@@             Coverage Diff             @@
##           master    #1549       +/-   ##
===========================================
+ Coverage   26.27%   53.04%   +26.77%     
===========================================
  Files         267      290       +23     
  Lines       24146    26114     +1968     
===========================================
+ Hits         6344    13852     +7508     
+ Misses      16984    10401     -6583     
- Partials      818     1861     +1043     

Flag	Coverage Δ
cluster	43.85% <ø> (?)
dm	26.18% <ø> (?)
integrate	47.54% <ø> (+31.39%)	⬆️
playground	13.78% <ø> (?)
tiup	?
unittest	22.75% <ø> (+<0.01%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
cmd/root.go	23.94% <ø> (-49.49%)	⬇️
main.go	0.00% <0.00%> (-100.00%)	⬇️
pkg/repository/utils/hash.go	0.00% <0.00%> (-83.34%)	⬇️
pkg/repository/model/publish.go	0.00% <0.00%> (-83.34%)	⬇️
cmd/env.go	27.77% <0.00%> (-66.67%)	⬇️
pkg/utils/args.go	0.00% <0.00%> (-50.00%)	⬇️
pkg/repository/model/model.go	0.00% <0.00%> (-47.52%)	⬇️
pkg/repository/v1manifest/repo.go	0.00% <0.00%> (-47.50%)	⬇️
cmd/uninstall.go	30.88% <0.00%> (-44.12%)	⬇️
... and 237 more

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[AstroProfundis]

/merge

[ti-chi-bot]

This pull request has been accepted and is ready to merge.

Commit hash: 2e859b0