Use long options when calling initdb

[tristan957]

Verbosity in this case is good when reading the code. Short options are better when operating in an interactive shell.

[github-actions]

5065 tests run: 4906 passed, 1 failed, 158 skipped (full report)

---

Failures on Postgres 15

• test_storage_controller_heartbeats[failure4]: release-x86-64

# Run all failed tests locally:
scripts/pytest -vv -n $(nproc) -k "test_storage_controller_heartbeats[release-pg15-failure4]"

Flaky tests (10)

Postgres 17

• test_pageserver_compaction_smoke: release-arm64
• test_backward_compatibility: release-x86-64
• test_aux_file_v2_flag[v2]: release-x86-64
• test_ondemand_wal_download_in_replication_slot_funcs: release-x86-64
• test_scrubber_physical_gc_ancestors[None]: release-x86-64
• test_restart_endpoint_after_switch_wal: release-x86-64

Postgres 15

• test_obsolete_slot_drop[cross-validation]: release-x86-64
• test_multixid_wraparound_import: release-x86-64
• test_sharding_split_stripe_size[65536]: release-x86-64
• test_subscriber_restart: release-x86-64

Code coverage* (full report)

• functions: 32.0% (7498 of 23402 functions)
• lines: 50.0% (60540 of 120960 lines)

* collected from Rust tests only

---

_{The comment gets automatically updated with the latest test results
697d147 at 2024-09-26T21:29:36.118Z :recycle:}

[yliang412]

LGTM