security: add steps to validate TLS between components (#20986)

[ti-chi-bot]

This is an automated cherry-pick of #20986

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• This PR is translated from:security: add steps to validate TLS between components docs#21811
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[ti-chi-bot]

@hfxsd This PR has conflicts, I have hold it.
Please resolve them or ask others to resolve them, then comment /unhold to remove the hold label.

[ti-chi-bot]

@ti-chi-bot: ## If you want to know how to resolve it, please read the guide in TiDB Dev Guide.

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[ti-chi-bot]

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[ti-chi-bot]

@ti-chi-bot: The following test failed, say /retest to rerun all failed tests or /retest-required to rerun all mandatory failed tests:

Test name	Commit	Details	Required	Rerun command
pull-verify	7ec7777	link	true	/test pull-verify

Full PR test history. Your PR dashboard.

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