ebs br: enhance TC validation

[BornChanger]

What problem does this PR solve?

Closes #5658

What is changed and how does it work?

For volume backup, this PR enhances the validation against the target TiDB cluster. That is if there is no TiKV stores or TiKV replica number is 0, the backup will fail.

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.

[BornChanger]

/cc @WangLe1321

[BornChanger]

/cc @YuJuncen

[ti-chi-bot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: WangLe1321

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Needs approval from an approver in each of these files:

• OWNERS [WangLe1321]

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[ti-chi-bot]

[LGTM Timeline notifier]

Timeline:

• 2024-06-06 13:17:54.593965874 +0000 UTC m=+38628.647277797: ☑️ agreed by WangLe1321.
• 2024-06-09 12:28:29.346139988 +0000 UTC m=+294863.399451913: ✖️🔁 reset by ti-chi-bot[bot].

[ti-chi-bot]

New changes are detected. LGTM label has been removed.

[BornChanger]

/run-pull-e2e-kind-br

[codecov-commenter]

Codecov Report

Attention: Patch coverage is 33.33333% with 4 lines in your changes missing coverage. Please review.

Project coverage is 21.07%. Comparing base (3897095) to head (f044720).
Report is 12 commits behind head on master.

Additional details and impacted files

@@             Coverage Diff             @@
##           master    #5659       +/-   ##
===========================================
- Coverage   61.46%   21.07%   -40.39%     
===========================================
  Files         235      219       -16     
  Lines       30397    30427       +30     
===========================================
- Hits        18683     6412    -12271     
- Misses       9840    23103    +13263     
+ Partials     1874      912      -962     

Flag	Coverage Δ
e2e	21.07% <33.33%> (?)
unittest	?

[csuzhangxc]

/cherry-pick release-1.5

[csuzhangxc]

/cherry-pick release-1.6

[ti-chi-bot]

@csuzhangxc: new pull request created to branch release-1.5: #5662.

In response to this:

/cherry-pick release-1.5

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]

@csuzhangxc: new pull request created to branch release-1.6: #5663.

In response to this:

/cherry-pick release-1.6

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.