[BugFix] VLLM_DISABLE_COMPILE_CACHE=1 should disable all reads and writes from the cache (#20942)

Signed-off-by: Richard Zou <zou3519@gmail.com>

vllm/compilation/compiler_interface.py

@@ -213,7 +213,9 @@ class InductorStandaloneAdaptor(CompilerInterface):
         # Save the compiled artifact to disk in the specified path
         assert key is not None
         path = os.path.join(self.cache_dir, key)
-        compiled_graph.save(path=path, format="unpacked")
+        if not envs.VLLM_DISABLE_COMPILE_CACHE:
+            compiled_graph.save(path=path, format="unpacked")
+            compilation_counter.num_compiled_artifacts_saved += 1
         return compiled_graph, (key, path)
 
     def load(self,