test: use aux file v2 policy in benchmarks

[skyzh]

Problem

Use aux file v2 in benchmarks.

Summary of changes

Checklist before requesting a review

• I have performed a self-review of my code.
• If it is a core feature, I have added thorough tests.
• Do we need to implement analytics? if so did you add the relevant metrics to the dashboard?
• If this PR requires public announcement, mark it with /release-notes label and add several sentences in this section.

Checklist before merging

• Do not forget to reformat commit message to not include the above checklist

[skyzh]

Decided not to enable v2 for all tests because some tests require the default value to be the same across regress + pageserver config. Only enabled it for benchmarks.

[github-actions]

3047 tests run: 2921 passed, 0 failed, 126 skipped (full report)

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Flaky tests (4)

Postgres 15

• test_subscriber_restart: release
• test_compaction_induced_by_detaches_in_history: release

Postgres 14

• test_pgbench_intensive_init_workload[neon_on-github-actions-selfhosted-1000]: release
• test_location_conf_churn[3]: debug

Code coverage* (full report)

• functions: 32.6% (6894 of 21124 functions)
• lines: 50.0% (53933 of 107928 lines)

* collected from Rust tests only

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_{The comment gets automatically updated with the latest test results
e9600aa at 2024-06-26T21:21:31.305Z :recycle:}