LibWeb: Add CanvasImageSource to ImageBitmapSource typedef

Author: https://github.com/Totto16
Commit: 9730e47d51
Pull-request: https://github.com/LadybirdBrowser/ladybird/pull/1715
Reviewed-by: https://github.com/gmta ✅
Reviewed-by: https://github.com/tcl3

Libraries/LibWeb/HTML/HTMLOrSVGElement.idl

@@ -1,3 +1,5 @@
+#import <HTML/DOMStringMap.idl>
+
 // https://html.spec.whatwg.org/#htmlorsvgelement
 interface mixin HTMLOrSVGElement {
     [SameObject] readonly attribute DOMStringMap dataset;