[bazel] Turn off LLVM_ENABLE_PLUGINS as it breaks TensorFlow Windows build

Author: norx1991

utils/bazel/llvm-project-overlay/llvm/include/llvm/Config/llvm-config.h

@@ -124,9 +124,6 @@
 /* Define to 1 if you have the DIA SDK installed, and to 0 if you don't. */
 #define LLVM_ENABLE_DIA_SDK 0
 
-/* Define if plugins enabled */
-#define LLVM_ENABLE_PLUGINS
-
 /* Define if building LLVM with LLVM_ENABLE_TELEMETRY */
 #define LLVM_ENABLE_TELEMETRY 1