blink: disables fast path parser for DOMParser

There seems to be an issue with quirks mode.

Bug: 330753862
Change-Id: I6b25289dbb000445a8f3b1de7796f0daa58f354f
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5368267
Commit-Queue: Scott Violet <sky@chromium.org>
Reviewed-by: Ian Kilpatrick <ikilpatrick@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1277021}

third_party/blink/renderer/platform/runtime_enabled_features.json5

@@ -1472,7 +1472,7 @@
     // of any issues.
     {
       name: "DOMParserUsesHTMLFastPathParser",
-      status: "stable"
+      status: "test"
     },
     {
       name: "DOMPartsAPI",