http-utils: generate heap profiles with jemalloc_pprof

[erikgrinaker]

Problem

The code to generate symbolized pprof heap profiles and flamegraph SVGs has been upstreamed to the jemalloc_pprof crate:

• Add symbolize feature for online symbolization polarsignals/rust-jemalloc-pprof#22
• Add flamegraph feature polarsignals/rust-jemalloc-pprof#23

Summary of changes

Use jemalloc_pprof to generate symbolized pprof heap profiles and flamegraph SVGs.

This reintroduces a bunch of internal jemalloc stack frames that we'd previously strip, e.g. each stack now always ends with prof_backtrace_impl (where jemalloc takes a stack trace for heap profiling), but that seems ok.

[github-actions]

7814 tests run: 7436 passed, 0 failed, 378 skipped (full report)

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Flaky tests (4)

Postgres 17

• test_pageserver_getpage_throttle: debug-x86-64-without-lfc
• test_check_visibility_map: debug-x86-64-without-lfc
• test_s3_wal_replay[local_fs]: release-arm64-without-lfc

Postgres 14

• test_storage_controller_heartbeats[failure2]: release-x86-64-with-lfc

Code coverage* (full report)

• functions: 32.9% (8677 of 26376 functions)
• lines: 48.8% (73899 of 151292 lines)

* collected from Rust tests only

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_{The comment gets automatically updated with the latest test results
91bf6c8 at 2025-03-04T12:22:46.215Z :recycle:}

[VladLazar]

Thanks for upstreaming!