With the introduction of test-local tenants and timelines, we can still
allow tests to share a pageserver and/or safekeeper, removing the overhead
of setting up those components.
Future work can add wrappers for Pageserver, Safekeepers, and other APIs
that expose tenant-level configuration options that shouldn't impact
concurrent or sequential tests that reuse the same PS/SK resources.
Important note: This doesn't yet work consistently for all updated tests.
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