chore(storage-scrubber): allow disable file logging

[skyzh]

Problem

part of https://github.com/neondatabase/cloud/issues/14024, k8s does not always have a volume available for logging, and I'm running into weird permission errors... While I could spend time figuring out how to create temp directories for logging, I think it would be better to just disable file logging as k8s containers are ephemeral and we cannot retrieve anything on the fs after the container gets removed.

Summary of changes

PAGESERVER_DISABLE_FILE_LOGGING=1 -> file logging disabled

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

[github-actions]

3067 tests run: 2952 passed, 0 failed, 115 skipped (full report)

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Flaky tests (2)

Postgres 16

• test_pg_regress[4]: debug
• test_tenant_creation_fails: debug

Code coverage* (full report)

• functions: 32.6% (6939 of 21281 functions)
• lines: 50.0% (54556 of 109075 lines)

* collected from Rust tests only

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_{The comment gets automatically updated with the latest test results
0a2969a at 2024-07-09T15:30:48.185Z :recycle:}