Replace ArrayListUnmanaged with ArrayList

src/SemanticTree.zig

@@ -225,7 +225,7 @@ fn walk(self: @This(), node: *Node, xpath_buffer: *std.ArrayList(u8), parent_nam
 }
 
 fn extractSelectOptions(node: *Node, page: *Page, arena: std.mem.Allocator) ![]OptionData {
-    var options = std.ArrayListUnmanaged(OptionData){};
+    var options: std.ArrayList(OptionData) = .empty;
     var it = node.childrenIterator();
     while (it.next()) |child| {
         if (child.is(Element)) |el| {

src/browser/webapi/css/CSSRuleList.zig

@@ -5,7 +5,7 @@ const CSSRule = @import("CSSRule.zig");
 
 const CSSRuleList = @This();
 
-_rules: std.ArrayListUnmanaged(*CSSRule) = .{},
+_rules: std.ArrayList(*CSSRule) = .empty,
 
 pub fn init(page: *Page) !*CSSRuleList {
     return page._factory.create(CSSRuleList{});

src/browser/webapi/css/StyleSheetList.zig

@@ -5,7 +5,7 @@ const CSSStyleSheet = @import("CSSStyleSheet.zig");
 
 const StyleSheetList = @This();
 
-_sheets: std.ArrayListUnmanaged(*CSSStyleSheet) = .{},
+_sheets: std.ArrayList(*CSSStyleSheet) = .empty,
 
 pub fn init(page: *Page) !*StyleSheetList {
     return page._factory.create(StyleSheetList{});