NFC: Remove unused includes (#133474)

diff --git a/mlir/lib/IR/Verifier.cpp b/mlir/lib/IR/Verifier.cpp
index 961ab75..f103137 100644
--- a/mlir/lib/IR/Verifier.cpp
+++ b/mlir/lib/IR/Verifier.cpp
@@ -31,13 +31,7 @@
 #include "mlir/IR/Operation.h"
 #include "mlir/IR/RegionKindInterface.h"
 #include "mlir/IR/Threading.h"
-#include "llvm/ADT/DenseMapInfoVariant.h"
 #include "llvm/ADT/PointerIntPair.h"
-#include "llvm/ADT/StringMap.h"
-#include "llvm/Support/FormatVariadic.h"
-#include "llvm/Support/PrettyStackTrace.h"
-#include "llvm/Support/Regex.h"
-#include <atomic>
 #include <optional>
 
 using namespace mlir;