LibWeb: Don't trim whitespace when checking for "module" type on scripts

No major engine allows whitespace in the type when checking for
"module".

This was also reflected in the relevant web platform test, but not in
the spec.

The spec has been changed to match this behaviour: https://github.com/whatwg/html/commit/23c723e3e94103e495a6b67e60ffc8a1a164334b

Userland/Libraries/LibWeb/HTML/HTMLScriptElement.cpp

@@ -126,12 +126,12 @@ void HTMLScriptElement::prepare_script()
         || (!has_type && !has_language)) {
         script_block_type = "text/javascript";
     } else if (has_type) {
-        script_block_type = attribute(HTML::AttributeNames::type).trim_whitespace();
+        script_block_type = attribute(HTML::AttributeNames::type);
     } else if (!attribute(HTML::AttributeNames::language).is_empty()) {
         script_block_type = String::formatted("text/{}", attribute(HTML::AttributeNames::language));
     }
 
-    if (is_javascript_mime_type_essence_match(script_block_type)) {
+    if (is_javascript_mime_type_essence_match(script_block_type.trim_whitespace())) {
         m_script_type = ScriptType::Classic;
     } else if (script_block_type.equals_ignoring_case("module")) {
         m_script_type = ScriptType::Module;