fix: retry only transient webhook failures

[qiancai]

What is changed, added or deleted? (Required)

Replace the webhook's manual retry loop with curl's transient-error retry behavior. This change:

• retries timeouts, connection refusals, rate limits, and transient server errors
• stops retrying permanent HTTP client errors
• preserves the existing attempt count, delay, and per-request timeouts

Which TiDB version(s) do your changes apply to? (Required)

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For details, see tips for choosing the affected versions.

• master (the latest development version)
• v9.0 (TiDB 9.0 versions)
• v8.5 (TiDB 8.5 versions)
• v8.1 (TiDB 8.1 versions)
• v7.5 (TiDB 7.5 versions)
• v7.1 (TiDB 7.1 versions)
• v6.5 (TiDB 6.5 versions)

What is the related PR or file link(s)?

• This PR is translated from:
• Other reference link(s): chore: notify on new GitHub issues #23356, chore: notify on new GitHub issues docs-cn#21836

AI agent involvement

• The changes in this PR were primarily made by an AI agent on behalf of the PR author.

Do your changes match any of the following descriptions?

• Delete files
• Change aliases
• Need modification after applied to another branch
• Might cause conflicts after applied to another branch

Summary by CodeRabbit

• Chores
  • Improved the reliability of automated issue notification delivery.
  • Notifications now retry transient connection failures more consistently and report unsuccessful requests more clearly.
  • Existing request content and timeout behavior remain unchanged.

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Path: .coderabbit.yaml

Review profile: ASSERTIVE

Plan: Pro Plus

Run ID: 3a9185de-ddda-4b24-b477-1abda0eb5029

📥 Commits

Reviewing files that changed from the base of the PR and between 7cdba03 and b708150.

📒 Files selected for processing (1)

• .github/workflows/bot.yaml

---

📝 Walkthrough

Walkthrough

The bot workflow replaces a manual three-attempt webhook retry loop with curl’s built-in retry, connection-refused handling, delay, and failure-reporting options while preserving the request payload, headers, URL, and timeout settings.

Changes

Webhook delivery

Layer / File(s)	Summary
Configure webhook retries .github/workflows/bot.yaml	The issue notification webhook uses curl-managed retries and --fail-with-body instead of shell-controlled retry messaging, sleeping, and exit handling.

Estimated code review effort: 2 (Simple) | ~5 minutes

Possibly related PRs

• pingcap/docs#23356: Modifies the same workflow webhook step to adjust delivery retry behavior.

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title clearly matches the main change: switching webhook retries to curl's transient-failure handling.
Description check	✅ Passed	The description covers the required sections, target version, references, and AI involvement, so it is mostly complete.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests

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[qiancai]

/approve

[ti-chi-bot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: qiancai

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• OWNERS [qiancai]

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