Add tests to ensure session is set correctly in OnChainScrapingVotes (#4821)

Co-authored-by: Bernhard Schuster <bernhard@ahoi.io>

polkadot/runtime/parachains/src/disputes.rs

@@ -1313,6 +1313,10 @@ fn check_signature(
 	}
 }
 
+#[cfg(test)]
+#[allow(unused_imports)]
+pub(crate) use self::tests::run_to_block;
+
 #[cfg(test)]
 mod tests {
 	use super::*;
@@ -1363,7 +1367,7 @@ mod tests {
 
 	// Run to specific block, while calling disputes pallet hooks manually, because disputes is not
 	// integrated in initializer yet.
-	fn run_to_block<'a>(
+	pub(crate) fn run_to_block<'a>(
 		to: BlockNumber,
 		new_session: impl Fn(BlockNumber) -> Option<NewSession<'a>>,
 	) {