ddl: fix panic in pause

[ywqzzy]

What problem does this PR solve?

Issue Number: close #47902

Problem Summary:
reorgCtx for reorgJob is cleaned up since worker is closed when calling isReorgPaused.

What is changed and how it works?

Use isReorgRunnable to ignore the check.

Check List

Tests

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

  • I checked and no code files have been changed.

Side effects

• Performance regression: Consumes more CPU
• Performance regression: Consumes more Memory
• Breaking backward compatibility

Documentation

• Affects user behaviors
• Contains syntax changes
• Contains variable changes
• Contains experimental features
• Changes MySQL compatibility

Release note

Please refer to Release Notes Language Style Guide to write a quality release note.

None

[tiprow]

Hi @ywqzzy. Thanks for your PR.

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[codecov]

Codecov Report

Merging #47914 (4e0cce7) into master (aa453de) will increase coverage by 1.0344%.
Report is 33 commits behind head on master.
The diff coverage is 0.0000%.

Additional details and impacted files

@@               Coverage Diff                @@
##             master     #47914        +/-   ##
================================================
+ Coverage   71.8945%   72.9289%   +1.0344%     
================================================
  Files          1398       1423        +25     
  Lines        405142     412644      +7502     
================================================
+ Hits         291275     300937      +9662     
+ Misses        94250      92875      -1375     
+ Partials      19617      18832       -785     

Flag	Coverage Δ
integration	41.9908% <0.0000%> (?)
unit	71.8796% <0.0000%> (-0.0149%)	⬇️

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

Components	Coverage Δ
dumpling	53.9913% <ø> (ø)
parser	∅ <ø> (∅)
br	48.9495% <ø> (-3.9918%)	⬇️

[hawkingrei]

/ok-to-test

[ywqzzy]

/cc @zimulala

[ti-chi-bot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: tangenta, wjhuang2016

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• OWNERS [tangenta,wjhuang2016]

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[ti-chi-bot]

[LGTM Timeline notifier]

Timeline:

• 2023-10-23 06:04:33.590747536 +0000 UTC m=+2241871.177857681: ☑️ agreed by tangenta.
• 2023-10-23 07:42:32.838368475 +0000 UTC m=+2247750.425478621: ☑️ agreed by wjhuang2016.

[ti-chi-bot]

In response to a cherrypick label: new pull request created to branch release-7.5: #47933.