scripts: update rust-analyzer for local alloc

Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

Author: ojeda

scripts/generate_rust_analyzer.py

@@ -56,8 +56,8 @@ def append_crate(display_name, root_module, is_workspace_member, deps, cfg):
 
     append_crate(
         "alloc",
-        sysroot_src / "alloc" / "src" / "lib.rs",
-        False,
+        srctree / "rust" / "alloc" / "lib.rs",
+        True,
         ["core", "compiler_builtins"],
         [],
     )