ddl: consider paused job when check runnable (#54419)

[ti-chi-bot]

This is an automated cherry-pick of #54419

What problem does this PR solve?

Issue Number: close #54383, ref #53246

Problem Summary:

	session 1	session 2	session 3
t1	create table t (a int); OK
t2		alter table t modify column a tinyint; -- job 1
t3	admin pause ddl jobs 1; OK	Paused
t4		Paused	alter table t add column c int;
			// Should be blocked!

As the table shown above, we run add column when the previous job modify column is not finished. This is unexpected because they reference the same table.

What changed and how does it work?

This PR moves the unfinished jobs to pending jobs after delivery2Worker() complete, in order to prevent getJob() obtaining new jobs that affect the same table.

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

[codecov]

Codecov Report

Attention: Patch coverage is 80.00000% with 12 lines in your changes missing coverage. Please review.

Please upload report for BASE (release-8.2@dc816da). Learn more about missing BASE report.

Additional details and impacted files

@@               Coverage Diff                @@
##             release-8.2     #54431   +/-   ##
================================================
  Coverage               ?   56.0055%           
================================================
  Files                  ?       1639           
  Lines                  ?     606693           
  Branches               ?          0           
================================================
  Hits                   ?     339782           
  Misses                 ?     243699           
  Partials               ?      23212           

Flag	Coverage Δ
integration	37.1614% <80.0000%> (?)

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

Components	Coverage Δ
dumpling	52.9656% <0.0000%> (?)
parser	∅ <0.0000%> (?)
br	52.7404% <0.0000%> (?)

[ti-chi-bot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: D3Hunter, tangenta

The full list of commands accepted by this bot can be found here.

The pull request process is described here

Needs approval from an approver in each of these files:

• pkg/ddl/OWNERS [tangenta]

Approvers can indicate their approval by writing /approve in a comment
Approvers can cancel approval by writing /approve cancel in a comment

[ti-chi-bot]

[LGTM Timeline notifier]

Timeline:

• 2024-07-04 05:47:49.687688427 +0000 UTC m=+1476196.173177260: ☑️ agreed by D3Hunter.
• 2024-07-04 06:02:02.661918066 +0000 UTC m=+1477049.147406899: ☑️ agreed by tangenta.