etcd/client (ticdc): Prevent revision in WatchWitchChan fallback. (#3851)

[ti-chi-bot]

This is an automated cherry-pick of #3851

What problem does this PR solve?

ref: #3615
ref: #4549

Prevent revision rollback.

Note: Before this PR merge, the lastRevision in WatchWitchChan is initialized to 0. When the watchCh is reset since there has no message been received , revision will be set to 0+1.
This may result in receiving some messages that do not need to be received, lead to a certain extend of performance loss, but it will not cause any correctness problems.

What is changed and how it works?

Clear and simple in code.

Check List

Tests

• Unit test

Related changes

• Need to cherry-pick to the release branch

Release note

None

[ti-chi-bot]

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[asddongmen]

/run-all-tests

[codecov-commenter]

Codecov Report

❗ No coverage uploaded for pull request base (release-5.2@d593b56). Click here to learn what that means.
The diff coverage is n/a.

@@               Coverage Diff                @@
##             release-5.2      #3926   +/-   ##
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  Coverage               ?   57.3773%           
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  Files                  ?        194           
  Lines                  ?      19431           
  Branches               ?          0           
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  Hits                   ?      11149           
  Misses                 ?       7314           
  Partials               ?        968           

[asddongmen]

/run-integration-tests

[asddongmen]

/merge

[ti-chi-bot]

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

Commit hash: 0ce7ad9

[ti-chi-bot]

@ti-chi-bot: Your PR was out of date, I have automatically updated it for you.

At the same time I will also trigger all tests for you:

/run-all-tests

If the CI test fails, you just re-trigger the test that failed and the bot will merge the PR for you after the CI passes.

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.

[asddongmen]

/run-kafka-integration-tests