Release docs: add new section about troubleshooting the release

[oandregal]

What?

Adds a new "Troubleshooting" section in the release docs.

Why?

There's an issue that happens occasionally that we're investigating. It's good to have it documented so people know how to proceed. See #55295

See thread in core-editor slack channel about the 17.1 release.

How?

Adds a new troubleshooting section in the release docs.

Test

See Troubleshooting the release.

[github-actions]

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[ockham]

LGTM, thank you for documenting this!