Fix content history diff error (#42755)

Author: C-Lodder

build/media_source/com_contenthistory/joomla.asset.json

@@ -10,7 +10,8 @@
       "type": "script",
       "uri": "com_contenthistory/admin-compare-compare.min.js",
       "dependencies": [
-        "core"
+        "core",
+        "diff"
       ],
       "attributes": {
         "type": "module"