fix(query-core) export Mutation class instead of exporting it as a type (#7793)

* fix(query-core) export Mutation class instead of exporting it as a type

previously, attempting to create a Mutation in a vanilla JS project required the use of the Mutation class constructor but due to it being exported as a type, we run into a runtime error stating that the Mutation type is not a class resulting in us not being able to proceed despite the compilation process in TypeScript not throwing an issue. This change exposes the class instead of the type in order to accomodate this requirement in vanilla JS projects

fixes `Mutation` class isn't exposed from @tanstack/query-core #7785

* ci: apply automated fixes

---------

Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com>
Co-authored-by: Dominik Dorfmeister <office@dorfmeister.cc>

Author: 3 people

packages/query-core/src/index.ts

@@ -35,7 +35,8 @@ export {
 export * from './types'
 export type { QueryState } from './query'
 export { Query } from './query'
-export type { Mutation, MutationState } from './mutation'
+export type { MutationState } from './mutation'
+export { Mutation } from './mutation'
 export type {
   DehydrateOptions,
   DehydratedState,