fix(curriculum): Merge Sort algorithm step 10 requires spaces to pass (freeCodeCamp#55980)

Co-authored-by: Lasse Jørgensen <[email protected]>

Author: subhadipjana866

curriculum/challenges/english/07-scientific-computing-with-python/learn-data-structures-by-building-the-merge-sort-algorithm/656680b0fc79f2c38a34d90e.md

@@ -24,7 +24,7 @@ You should have a variable named `left_array_index` inside your `merge_sort` fun
     const merge_sort = __helpers.python.getDef("\n" + transformedCode, "merge_sort");
     const { function_body } = merge_sort;
 
-    assert.match(function_body, /left_array_index\s*(?!=)/);
+    assert.match(function_body, /left_array_index/);
   }
 })
 ```
@@ -52,7 +52,7 @@ You should have a variable named `right_array_index` inside your `merge_sort` fu
     const merge_sort = __helpers.python.getDef("\n" + transformedCode, "merge_sort");
     const { function_body } = merge_sort;
 
-    assert.match(function_body, /right_array_index\s*(?!=)/);
+    assert.match(function_body, /right_array_index/);
   }
 })
 ```
@@ -81,7 +81,7 @@ You should have a variable named `sorted_index` inside your `merge_sort` functio
     const merge_sort = __helpers.python.getDef("\n" + transformedCode, "merge_sort");
     const { function_body } = merge_sort;
 
-    assert.match(function_body, /sorted_index\s*(?!=)/);
+    assert.match(function_body, /sorted_index/);
   }
 })
 ```