Install node-gyp before rebuilding pprof native binding

node_modules/.bin/node-gyp was not found because node-gyp was not
explicitly installed in the pprof-source workdir. Add an explicit
npm install step to make it available.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: JackStrohm-asana

Dockerfile.Packages

@@ -36,6 +36,7 @@ RUN npm i @datadog/pprof@5.8.0 --ignore-scripts
 RUN git clone --branch v5.8.0 --depth 1 https://github.com/DataDog/pprof-nodejs.git /usr/src/pprof-source
 WORKDIR /usr/src/pprof-source
 RUN npm install --ignore-scripts
+RUN npm install --unsafe-perm node-gyp
 RUN npm_config_nodedir="/usr/src/node/node-install/usr/local" node_modules/.bin/node-gyp rebuild --jobs=max
 # Replace the linux prebuilt with our pointer-compression-compatible binary.
 # NODE_MODULE_VERSION and arch are read dynamically from the custom Node binary.