rename none to null

tree-sitter-brolang/test/corpus/syntax.txt

@@ -211,7 +211,7 @@ main func() void {
 Intrinsic type construction
 ==================
 
-Generated :: alias struct_type!(.auto, {"value"}, {i32}, {none})
+Generated :: alias struct_type!(.auto, {"value"}, {i32}, {null})
 
 ---
 
@@ -238,7 +238,7 @@ Generated :: alias struct_type!(.auto, {"value"}, {i32}, {none})
             (expression
               (tuple_literal
                 (expression
-                  (none))))))))))
+                  (null))))))))))
 
 ==================
 Errdefer

tree-sitter-brolang/test/highlight/types.bro

@@ -20,5 +20,5 @@ clear func($K, $V type) void {
 #                    ^ operator
 }
 
-Generated :: alias struct_type!(.auto, {"value"}, {i32}, {none})
+Generated :: alias struct_type!(.auto, {"value"}, {i32}, {null})
 #                  ^^^^^^^^^^^^ function.builtin