pageserver: remove no-op attempt to report fail/failpoint feature

[jcsp]

Problem

The current output from a prod binary at startup is:

git-env:765455bca22700e49c053d47f44f58a6df7c321f failpoints: true, features: [] launch_timestamp: 2023-08-02 10:30:35.545217477 UTC

It's confusing to read that line, then read the code and think "if failpoints is true, but not in the features list, what does that mean?". As far as I can tell, the check of fail/failpoints is just always false because cargo doesn't expose features across crates like this: the fail/failpoints syntax works in the cargo CLI but not from a macro in some crate other than fail.

Summary of changes

Remove the lines that try to check fail/failpoints from the pageserver entrypoint module. This has no functional impact but makes the code slightly easier to understand when trying to make sense of the line printed on startup.

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]

1264 tests run: 1215 passed, 0 failed, 49 skipped (full report)

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Flaky tests (1)

Postgres 15

• test_crafted_wal_end[last_wal_record_crossing_segment]: debug

[LizardWizzard]

LGTM

As an alternative we can manually add failpoint feature flag into features list, but that probably doesnt worth the effort and doesnt make a big difference