Auto merge of #25410 - pshaughn:ceupgrade, r=jdm

Implement CustomElementRegistry.upgrade

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An additional small change will be needed if whatwg/html#5126 lands, which will pass an infinite recursion test this is currently failing in custom-elements/upgrading.html (right now the test is asking for behavior that isn't in the spec).
The remaining test in custom-elements/custom-element-registry/upgrade.html is because it needs shadow DOM.

---
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- [X] `./mach build -d` does not report any errors
- [X] `./mach test-tidy` does not report any errors
- [X] These changes fix #24989

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- [X] There are tests for these changes

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tests/wpt/metadata/custom-elements/custom-element-registry/upgrade.html.ini

@@ -1,16 +1,4 @@
 [upgrade.html]
-  [Upgrading an element directly (example from the spec)]
-    expected: FAIL
-
-  [Two elements as children of the upgraded node]
-    expected: FAIL
-
-  [Two elements as descendants of the upgraded node]
-    expected: FAIL
-
   [Two elements as shadow-including descendants (and not descendants) of the upgraded node]
     expected: FAIL
 
-  [Elements inside a template contents DocumentFragment node]
-    expected: FAIL
-

tests/wpt/metadata/html/dom/idlharness.https.html.ini

@@ -62,9 +62,6 @@
   [CanvasRenderingContext2D interface: document.createElement("canvas").getContext("2d") must inherit property "getTransform()" with the proper type]
     expected: FAIL
 
-  [CustomElementRegistry interface: operation upgrade(Node)]
-    expected: FAIL
-
   [OffscreenCanvasRenderingContext2D interface: attribute imageSmoothingEnabled]
     expected: FAIL