[ADT] Remove any_isa (NFC) (llvm#65636)

any_isa has been deprecated since:

  commit bb7940e
  Author: Sebastian Neubauer <[email protected]>
  Date:   Tue Dec 20 13:28:30 2022 +0100

Author: kazutakahirata

llvm/include/llvm/ADT/Any.h

@@ -135,12 +135,6 @@ class LLVM_EXTERNAL_VISIBILITY Any {
 // See also https://github.com/llvm/llvm-project/issues/62270
 template <typename T> char Any::TypeId<T>::Id = 1;
 
-template <typename T>
-LLVM_DEPRECATED("Use any_cast(Any*) != nullptr instead", "any_cast")
-bool any_isa(const Any &Value) {
-  return Value.isa<T>();
-}
-
 template <class T> T any_cast(const Any &Value) {
   assert(Value.isa<T>() && "Bad any cast!");
   return static_cast<T>(*any_cast<remove_cvref_t<T>>(&Value));