Remove edits feature flag from docs and config

Part of https://github.com/vector-im/riot-web/issues/10282

config.sample.json

@@ -23,8 +23,7 @@
     "features": {
         "feature_groups": "labs",
         "feature_pinning": "labs",
-        "feature_reactions": "labs",
-        "feature_message_editing": "labs"
+        "feature_reactions": "labs"
     },
     "default_federate": true,
     "default_theme": "light",

docs/labs.md

@@ -35,11 +35,4 @@ That's it. Now should see your new counter under the header.
 reactions from other people. This feature is currently under active development,
 and only portions have been implemented so far.
 
-## Message editing
-
-`feature_message_editing` allows editing messages after they have been sent,
-accessible from the reaction/context bar when hovering a message.
-This feature is currently under active development,
-and only portions have been implemented so far.
-
 [#riot-web:matrix.org]: https://matrix.to/#/#riot-web:matrix.org

electron_app/riot.im/config.json

@@ -31,8 +31,7 @@
     },
     "features": {
         "feature_lazyloading": "enable",
-        "feature_reactions": "enable",
-        "feature_message_editing": "enable"
+        "feature_reactions": "enable"
     },
     "enable_presence_by_hs_url": {
         "https://matrix.org": false