fix(syncoid): regather $snaps on --delete-target-snapshots flag

syncoid

@@ -980,6 +980,16 @@ sub syncdataset {
 		# those that exist on the source. Remaining are the snapshots
 		# that are only on the target. Then sort by creation date, as
 		# to remove the oldest snapshots first.
+
+		# regather snapshots on source and target
+		%snaps = getsnaps('source',$sourcehost,$sourcefs,$sourceisroot);
+
+                if ($targetexists) {
+                    my %targetsnaps = getsnaps('target',$targethost,$targetfs,$targetisroot);
+                    my %sourcesnaps = %snaps;
+                    %snaps = (%sourcesnaps, %targetsnaps);
+                }
+
 		my @to_delete = sort { $snaps{'target'}{$a}{'creation'}<=>$snaps{'target'}{$b}{'creation'} } grep {!exists $snaps{'source'}{$_}} keys %{ $snaps{'target'} };
 		while (@to_delete) {
 			# Create batch of snapshots to remove