Bug 1887845 - Enabled `dom.events.asyncClipboard.clipboardItem` by default; r=nika

Differential Revision: https://phabricator.services.mozilla.com/D207973

dom/tests/mochitest/general/test_interfaces.js

@@ -257,7 +257,7 @@ let interfaceNamesInGlobalScope = [
   // IMPORTANT: Do not change this list without review from a DOM peer!
   { name: "ClipboardEvent", insecureContext: true },
   // IMPORTANT: Do not change this list without review from a DOM peer!
-  { name: "ClipboardItem", earlyBetaOrEarlier: true },
+  { name: "ClipboardItem" },
   // IMPORTANT: Do not change this list without review from a DOM peer!
   { name: "CloseEvent", insecureContext: true },
   // IMPORTANT: Do not change this list without review from a DOM peer!

modules/libpref/init/StaticPrefList.yaml

@@ -2563,7 +2563,7 @@
 # to content.
 - name: dom.events.asyncClipboard.clipboardItem
   type: bool
-  value: @IS_EARLY_BETA_OR_EARLIER@
+  value: true
   mirror: always
 
 # Skips checking permission and user activation when accessing the clipboard.