fix: use --no-ff --no-commit for Don't Commit option in merge popup to ensure branch is not changed or updated with fast-forward commits (#532)

Author: love-linger

src/Models/MergeMode.cs

@@ -7,7 +7,7 @@ public class MergeMode
             new MergeMode("Default", "Fast-forward if possible", ""),
             new MergeMode("No Fast-forward", "Always create a merge commit", "--no-ff"),
             new MergeMode("Squash", "Use '--squash'", "--squash"),
-            new MergeMode("Don't commit", "Merge without commit", "--no-commit"),
+            new MergeMode("Don't commit", "Merge without commit", "--no-ff --no-commit"),
         ];
 
         public string Name { get; set; }