Bug 1709269 - [devtools] Remove target-configuration watcher trait r=nchevobbe

Depends on D114217

Differential Revision: https://phabricator.services.mozilla.com/D114218

devtools/server/actors/watcher.js

@@ -162,12 +162,6 @@ exports.WatcherActor = protocol.ActorClassWithSpec(watcherSpec, {
           [Resources.TYPES.SERVER_SENT_EVENT]: hasBrowserElement,
           [Resources.TYPES.WEBSOCKET]: hasBrowserElement,
         },
-        // @backward-compat { version 87 } Starting with FF87, if the watcher is
-        // supported, the TargetConfiguration actor can be used to set configuration
-        // flags which impact BrowsingContext targets.
-        // When removing this trait, consumers should still check that the Watcher is
-        // available.
-        "target-configuration": true,
         // @backward-compat { version 88 } Starting with FF88, if the watcher is
         // supported, the ThreadConfiguration actor can be used to maintain thread configuration
         // options.

devtools/shared/commands/target-configuration/target-configuration-command.js

@@ -35,9 +35,7 @@ class TargetConfigurationCommand {
   }
 
   _hasTargetWatcherSupport() {
-    return this._commands.targetCommand.hasTargetWatcherSupport(
-      "target-configuration"
-    );
+    return this._commands.targetCommand.hasTargetWatcherSupport();
   }
 
   /**