[github][mlir] Add kuhar to code owners for vector IR (#99955)

This is so that I can track vector dialect changes and pay attention to
the maintenance required on the SPIR-V lowering side.

Author: kuhar

.github/CODEOWNERS

@@ -86,6 +86,7 @@ clang/test/AST/Interp/ @tbaederr
 /mlir/**/*VectorToLLVM* @banach-space @dcaballe @nicolasvasilache
 /mlir/**/*X86Vector* @aartbik @dcaballe @nicolasvasilache
 /mlir/include/mlir/Dialect/Vector @banach-space @dcaballe @nicolasvasilache
+/mlir/include/mlir/Dialect/Vector/IR @kuhar
 /mlir/lib/Dialect/Vector @banach-space @dcaballe @nicolasvasilache
 /mlir/lib/Dialect/Vector/Transforms/* @banach-space @dcaballe @hanhanW @nicolasvasilache
 /mlir/lib/Dialect/Vector/Transforms/VectorEmulateNarrowType.cpp @banach-space @dcaballe @MaheshRavishankar @nicolasvasilache