Remove deprecated getOperationRootType (#3571)

Author: IvanGoncharov

src/index.ts

@@ -402,8 +402,6 @@ export {
   getIntrospectionQuery,
   // Gets the target Operation from a Document.
   getOperationAST,
-  // Gets the Type for the target Operation AST.
-  getOperationRootType,
   // Convert a GraphQLSchema to an IntrospectionQuery.
   introspectionFromSchema,
   // Build a GraphQLSchema from an introspection result.

src/utilities/__tests__/getOperationRootType-test.ts

@@ -29,9 +29,6 @@ export type {
 // Gets the target Operation from a Document.
 export { getOperationAST } from './getOperationAST';
 
-// Gets the Type for the target Operation AST.
-export { getOperationRootType } from './getOperationRootType';
-
 // Convert a GraphQLSchema to an IntrospectionQuery.
 export { introspectionFromSchema } from './introspectionFromSchema';