Fix Typos in Comments and Error Messages in pallet-xcm (#8645)

**Description:**  
This pull request corrects minor typos in the `pallet-xcm` module:

- In `benchmarking.rs`, the error message for version conversion was
updated for consistency.
- In `lib.rs`, the word "Futhermore" in a comment was corrected to
"Furthermore".

These changes improve code readability and maintain consistency in
documentation and error messages. No functional or logic changes were
made.

---------

Co-authored-by: Bastian Köcher <[email protected]>

Author: leopardracer

polkadot/xcm/pallet-xcm/src/benchmarking.rs

@@ -470,7 +470,7 @@ mod benchmarks {
 		let bad_location: Location = Plurality { id: BodyId::Unit, part: BodyPart::Voice }.into();
 		let bad_location = VersionedLocation::from(bad_location)
 			.into_version(older_xcm_version)
-			.expect("Version convertion should work");
+			.expect("Version conversion should work");
 		let current_version = T::AdvertisedXcmVersion::get();
 		VersionNotifyTargets::<T>::insert(
 			current_version,

polkadot/xcm/pallet-xcm/src/lib.rs

@@ -3421,7 +3421,7 @@ impl<T: Config> Pallet<T> {
 	/// NOTE: `notify` gets called as part of handling an incoming message, so it should be
 	/// lightweight. Its weight is estimated during this function and stored ready for
 	/// weighing `ReportOutcome` on the way back. If it turns out to be heavier once it returns
-	/// then reporting the outcome will fail. Futhermore if the estimate is too high, then it
+	/// then reporting the outcome will fail. Furthermore if the estimate is too high, then it
 	/// may be put in the overweight queue and need to be manually executed.
 	pub fn report_outcome_notify(
 		message: &mut Xcm<()>,