Address review: take the runspace lock on both dispose paths

Co-authored-by: jessehouwing <4173387+jessehouwing@users.noreply.github.com>

Author: Copilot

Engine/CommandInfoCache.cs

@@ -57,24 +57,23 @@ public void Dispose()
 
         protected virtual void Dispose(bool disposing)
         {
-            if ( disposed )
+            // Always take the lock, also on the finalizer path, so that 'disposed' is never
+            // published without the runspace being disposed along with it and so that the runspace
+            // cannot be disposed while a lookup is in flight.
+            lock (_runspaceLock)
             {
-                return;
-            }
+                if ( disposed )
+                {
+                    return;
+                }
 
-            if ( disposing )
-            {
-                // Take the lock so that the runspace is not disposed while a lookup is in flight.
-                lock (_runspaceLock)
+                disposed = true;
+
+                if ( disposing )
                 {
-                    disposed = true;
                     _runspace.Dispose();
                 }
-
-                return;
             }
-
-            disposed = true;
         }
 
         /// <summary>