[mlir][linalg][python] Add auto-generated file warning (NFC).

Annotate LinalgNamedStructuredOps.yaml with a comment stating the file is auto-generated and should not be edited manually.

Reviewed By: nicolasvasilache

Differential Revision: https://reviews.llvm.org/D105809

mlir/include/mlir/Dialect/Linalg/IR/LinalgNamedStructuredOps.yaml

@@ -1,3 +1,4 @@
+# Auto-generated file. Do not edit!
 --- !LinalgOpConfig
 metadata: !LinalgOpMetadata
   name: matmul

mlir/python/mlir/dialects/linalg/opdsl/dump_oplib.py

@@ -81,6 +81,7 @@ def main(args):
 
   # Print.
   if args.format == "yaml":
+    print("# Auto-generated file. Do not edit!")
     print(yaml_dump_all(configs))
   elif args.format == "repr":
     for config in configs: