executor: check gc safe time first when iterate the history ddl jobs (#18380)

[ti-srebot]

cherry-pick #18380 to release-3.0

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Signed-off-by: crazycs520 crazycs520@gmail.com

What problem does this PR solve?

When requesting the /tiflash/replica HTTP API, it will iterate the history DDL job to find the dropped table that has not been GC.

Before this PR, if the TiDB cluster has not done the drop table or drop database DDL jobs, the /tiflash/replica HTTP API will iterate all DDL jobs, it would be very slow when there are many history DDL jobs.

How to avoid this problem before this PR?

You can simply create a random table and then drop it, then after the GC safe time passed, then request the /tiflash/replica HTTP API will be normal speed.

use test;
create table random_t (a int);
drop table random_t;

What is changed and how it works?

check gc safe time first when iterate the history ddl jobs.

Related changes

• Need to cherry-pick to the release branch

Check List

Tests

• Manual test (add detailed scripts or steps below)

1.  execute a lot of DDL jobs (such 1W) except for `drop table/drop database`
2. wait after passed the GC safe point.
3. time curl http://{$TIDB_ADDR}/tiflash/replica 

Side effects

• No

Release note

• Fix the issue of request /tiflash/replica HTTP API was slow when there are many history DDL jobs in TiDB cluster.

[ti-srebot]

/run-all-tests

[crazycs520]

/run-all-tests

[tangenta]

LGTM

[ti-srebot]

@tangenta,Thanks for your review. However, LGTM is restricted to Reviewers or higher roles.See the corresponding SIG page for more information. Related SIGs: execution(slack).

[AilinKid]

LGTM

[ti-srebot]

@AilinKid,Thanks for your review. However, LGTM is restricted to Reviewers or higher roles.See the corresponding SIG page for more information. Related SIGs: execution(slack).

[crazycs520]

/run-all-tests

[ti-srebot]

@AilinKid,Thanks for your review. However, LGTM is restricted to Reviewers or higher roles.See the corresponding SIG page for more information. Related SIGs: execution(slack).

[crazycs520]

/run-unit-test