Mark ShadowRoot.p.delegatesFocus non-standard (#7620)

This change marks ShadowRoot.prototype.delegatesFocus standard_track:false
and deprecated:true. https://dom.spec.whatwg.org/#interface-shadowroot
doesn’t actually define any such exposed property — neither for
ShadowRoot nor for the interfaces it inherits from.

Blink/Chrome does expose such a property, but that’s not due to any
actual spec requirements.

Related:
mdn/sprints#3917
whatwg/dom#931

api/ShadowRoot.json

@@ -116,8 +116,8 @@
           },
           "status": {
             "experimental": true,
-            "standard_track": true,
-            "deprecated": false
+            "standard_track": false,
+            "deprecated": true
           }
         }
       },