refactor(profiling): depend on published libdd-profiling-heap-gotter crate

Migrate the native heap-gotter cdylib wrapper off the unpublished libdatadog
`main` git pin (rev a10f667e) and onto the published crates.io release
`libdd-profiling-heap-gotter` 1.0.0 (published 2026-07-22).

The upstream crate was renamed (from the never-published
`libdd-profiling-heap-gotter-ffi`) and now exposes a pure-Rust API instead of
the `ddog_*` C-ABI surface, so lib.rs is updated to call
`install_heap_overrides()` / `heap_overrides_are_installed()` /
`test_hook_hits()`. Our exported `ddtrace_heap_gotter_*` C symbols keep the
same names and signatures, so the ctypes activator (PR B) is unaffected.

Verified with `cargo check`/`cargo build --release` against crates.io;
Cargo.lock drops the libdatadog `main` transitive tree and pins gotter+sampler
1.0.0.

Author: vlad-scherbich

setup.py

@@ -113,8 +113,8 @@
 IS_EDITABLE = False  # Set to True if the package is being installed in editable mode
 
 NATIVE_CRATE = HERE / "src" / "native"
-# Standalone cdylib wrapper around libdatadog's heap-gotter FFI. Built out-of-band
-# (opt-in) because it pins libdatadog `main` rather than the tagged `src/native` rev.
+# Standalone cdylib wrapper around libdatadog's published `libdd-profiling-heap-gotter`
+# crate (crates.io). Built out-of-band (opt-in) from the tagged `src/native` build.
 NATIVE_HEAP_GOTTER_CRATE = HERE / "src" / "native_heap_gotter"
 DDTRACE_DIR = HERE / "ddtrace"
 LIBDDWAF_DOWNLOAD_DIR = DDTRACE_DIR / "appsec" / "_ddwaf" / "libddwaf"