log_backup: fix panic during advancer owner transfer (#52671)

[ti-chi-bot]

This is an automated cherry-pick of #52671

What problem does this PR solve?

Issue Number: close #52597

Problem Summary:

1. When losing the advancer ownership, the channel for subscription may be full.
2. the consumer has already gone due to the canceled context. Hence making the producer(subscription) goroutine stuck.
3. After the graceful shutdown period, the output channel will be eventually closed and we will get a send on closed channel panic.

What changed and how does it work?

• When sending to the channel, also select the context.
• Catch all panic and convert them to errors (so we can retry.)

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.

Fixed a bug where TiDB may panic when log backup enabled and PD is unreachable.

[YuJuncen]

/test unit-test

[tiprow]

@YuJuncen: No presubmit jobs available for pingcap/tidb@release-6.5

In response to this:

/test unit-test

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 kubernetes-sigs/prow repository.

[ti-chi-bot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: Leavrth, YuJuncen

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:

• OWNERS [Leavrth,YuJuncen]

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:

• 2024-06-06 03:29:53.130125683 +0000 UTC m=+3347.183437601: ☑️ agreed by YuJuncen.
• 2024-06-06 05:13:56.034825649 +0000 UTC m=+9590.088137567: ☑️ agreed by Leavrth.

[codecov]

Codecov Report

Attention: Patch coverage is 95.74468% with 2 lines in your changes missing coverage. Please review.

Please upload report for BASE (release-6.5@d9c5bf6). Learn more about missing BASE report.

Additional details and impacted files

@@               Coverage Diff                @@
##             release-6.5     #53703   +/-   ##
================================================
  Coverage               ?   73.6529%           
================================================
  Files                  ?       1096           
  Lines                  ?     351861           
  Branches               ?          0           
================================================
  Hits                   ?     259156           
  Misses                 ?      76037           
  Partials               ?      16668