storcon: update compute hook state on detach

[VladLazar]

Problem

Previously, the storage controller may send compute notifications containing stale pageservers (i.e. pageserver serving the shard was detached). This happened because detaches did not update the compute hook state.

Summary of Changes

Update compute hook state on shard detach.

Fixes #8928

[github-actions]

4994 tests run: 4830 passed, 0 failed, 164 skipped (full report)

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Flaky tests (8)

Postgres 17

• test_pageserver_compaction_smoke: release-arm64

Postgres 16

• test_slots_and_branching: release-x86-64
• test_replica_start_scan_clog_crashed_xids: release-arm64

Postgres 15

• test_ondemand_wal_download_in_replication_slot_funcs: release-arm64, release-x86-64
• test_storage_controller_onboarding[True]: release-x86-64
• test_subscriber_restart: release-arm64

Postgres 14

• test_location_conf_churn[3]: release-x86-64

Code coverage* (full report)

• functions: 31.8% (7419 of 23308 functions)
• lines: 49.8% (59586 of 119702 lines)

* collected from Rust tests only

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_{The comment gets automatically updated with the latest test results
9e47dbb at 2024-09-19T13:35:27.005Z :recycle:}

[koivunej]

• test_gc_of_remote_layers: release-arm64

Not entirely sure why would this PR cause this test failure, it has not happened in a long while.