Increase reconciler timeout after shard split

[arpad-m]

Sometimes, especially when the host running the tests is overloaded, we can run into reconcile timeouts in test_timeline_ancestor_detach_idempotent_success, making the test flaky. By increasing the timeouts from 30 seconds to 120 seconds, we can address the flakiness.

Fixes #10464

[github-actions]

7381 tests run: 6996 passed, 0 failed, 385 skipped (full report)

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Flaky tests (2)

Postgres 17

• test_metrics_normal_work: debug-x86-64

Postgres 14

• test_metrics_normal_work: release-x86-64

Code coverage* (full report)

• functions: 33.5% (8490 of 25342 functions)
• lines: 49.3% (71373 of 144774 lines)

* collected from Rust tests only

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_{The comment gets automatically updated with the latest test results
4f6fa45 at 2025-01-23T16:42:47.073Z :recycle:}