Update version of kind to v0.11.1 and version of ubuntu to 20.04 (#4063)

[ti-srebot]

cherry-pick #4063 to release-1.2
You can switch your code base to this Pull Request by using git-extras:

# In tidb-operator repo:
git pr https://github.com/pingcap/tidb-operator/pull/4067

After apply modifications, you can push your change to this PR via:

git push git@github.com:ti-srebot/tidb-operator.git pr/4067:release-1.2-74ccda087708

---

What problem does this PR solve?

Close #4059

Ref kubernetes-sigs/kind#2241

What is changed and how does it work?

Code changes

• Has Go code change
• Has CI related scripts change

Tests

• Unit test
• E2E test
• Manual test
• No code

Side effects

• Breaking backward compatibility
• Other side effects:

Related changes

• Need to cherry-pick to the release branch
• Need to update the documentation

Release Notes

Please refer to Release Notes Language Style Guide before writing the release note.

[ti-srebot]

@KanShiori you're already a collaborator in bot's repo.

[codecov-commenter]

Codecov Report

Merging #4067 (bc936d2) into release-1.2 (bb24123) will increase coverage by 0.51%.
The diff coverage is n/a.

@@               Coverage Diff               @@
##           release-1.2    #4067      +/-   ##
===============================================
+ Coverage        70.36%   70.87%   +0.51%     
===============================================
  Files              182      182              
  Lines            19374    19374              
===============================================
+ Hits             13632    13731      +99     
+ Misses            4623     4507     -116     
- Partials          1119     1136      +17     

Flag	Coverage Δ
e2e	57.14% <ø> (+1.87%)	⬆️
unittest	61.14% <ø> (ø)

[DanielZhangQD]

/test pull-e2e-kind

[DanielZhangQD]

LGTM

[DanielZhangQD]

/merge

[ti-chi-bot]

@DanielZhangQD: /merge in this pull request requires 2 approval(s).

In response to this:

/merge

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the ti-community-infra/tichi repository.

[KanShiori]

/test pull-e2e-kind

[DanielZhangQD]

/merge

[ti-chi-bot]

@DanielZhangQD: /merge in this pull request requires 2 approval(s).

In response to this:

/merge

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the ti-community-infra/tichi repository.

[ti-chi-bot]

[REVIEW NOTIFICATION]

This pull request has been approved by:

• DanielZhangQD
• csuzhangxc

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[csuzhangxc]

/merge

[ti-chi-bot]

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

Commit hash: bc936d2