Disallow archived timelines to be detached or reparented

[arpad-m]

Disallow a request for timeline ancestor detach if either the to be detached timeline, or any of the to be reparented timelines are offloaded or archived.

In theory we could support timelines that are archived but not offloaded, but archived timelines are at the risk of being offloaded, so we treat them like offloaded timelines. As for offloaded timelines, any code to "support" them would amount to unoffloading them, at which point we can just demand to have the timelines be unarchived.

Part of #8088

[github-actions]

5328 tests run: 5106 passed, 0 failed, 222 skipped (full report)

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Flaky tests (1)

Postgres 17

• test_readonly_node_gc: debug-x86-64

Code coverage* (full report)

• functions: 31.5% (7758 of 24659 functions)
• lines: 49.0% (61005 of 124563 lines)

* collected from Rust tests only

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_{The comment gets automatically updated with the latest test results
3b96d57 at 2024-10-30T00:53:58.364Z :recycle:}