Offloaded timeline deletion

[arpad-m]

As pointed out in #9489 (comment) , we currently didn't support deletion for offloaded timelines after the timeline has been loaded from the manifest instead of having been offloaded.

This was because the upload queue hasn't been initialized yet. This PR thus initializes the timeline and shuts it down immediately.

Part of #8088

[github-actions]

5282 tests run: 5067 passed, 1 failed, 214 skipped (full report)

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Failures on Postgres 17

• test_sharding_split_failures[failure15]: debug-x86-64

# Run all failed tests locally:
scripts/pytest -vv -n $(nproc) -k "test_sharding_split_failures[debug-pg17-failure15]"

Flaky tests (3)

Postgres 17

• test_readonly_node_gc: debug-x86-64
• test_sharding_split_smoke: debug-x86-64
• test_timeline_detach_ancestor_interrupted_by_deletion[False-delete_timeline]: debug-x86-64

Code coverage* (full report)

• functions: 31.4% (7697 of 24540 functions)
• lines: 48.8% (60462 of 123841 lines)

* collected from Rust tests only

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_{The comment gets automatically updated with the latest test results
d418456 at 2024-10-26T13:34:26.111Z :recycle:}