ci(profiling): compile native heap gotter into Linux wheels

Set DD_PROFILING_NATIVE_HEAP_ENABLED on the Linux wheel job so
libdd_heap_gotter.so is packaged. Runtime arming stays off by default.

Author: vlad-scherbich

.gitlab/package.yml

@@ -96,6 +96,8 @@ variables:
     SCCACHE_BUCKET: "dd-trace-py-builds"
     SCCACHE_S3_KEY_PREFIX: "sccache"
     SCCACHE_REGION: "us-east-1"
+    # Packages the cdylib into Linux wheels only; does NOT arm the feature at customer runtime.
+    DD_PROFILING_NATIVE_HEAP_ENABLED: "1"
   parallel:
     matrix:
       - ARCH_TAG: "amd64"

ddtrace/internal/settings/profiling.py

@@ -560,7 +560,7 @@ class ProfilingConfigNativeHeap(DDConfig):
         help=(
             "Whether to enable experimental native (C/C++) heap profiling. "
             "Requires DD_PROFILING_ENABLED=true, Linux, and a wheel built with "
-            "DD_PROFILING_NATIVE_HEAP_BUILD=1. Disabled by default."
+            "DD_PROFILING_NATIVE_HEAP_ENABLED=1. Disabled by default."
         ),
     )