src: remove ref to tools/generate_code_cache.js

This commit removes the reference to tools/generate_code_cache.js
and replaces it with a note about more information being available
in tools/code_cache/README.md.

PR-URL: #33825
Reviewed-By: Richard Lau <riclau@uk.ibm.com>
Reviewed-By: David Carlier <devnexen@gmail.com>

src/node_code_cache_stub.cc

@@ -4,8 +4,10 @@
 
 #include "node_native_module_env.h"
 
-// This is supposed to be generated by tools/generate_code_cache.js
-// The stub here is used when configure is run without `--code-cache-path`
+// The stub here is used when configure is run without `--code-cache-path`.
+// When --code-cache-path is set this stub will not be used and instead
+// an implementation will be generated. See tools/code_cache/README.md for
+// more information.
 
 namespace node {
 namespace native_module {