fix: do not allow execution of invalid query in query cursor

Author: itsaky

android-tree-sitter/src/main/java/com/itsaky/androidide/treesitter/TSQueryCursor.java

@@ -30,6 +30,9 @@ public TSQueryCursor() {
 
   /** Start running the given query on the given node. */
   public void exec(TSQuery query, TSNode node) {
+    if (query == null || !query.isValid()) {
+      throw new IllegalArgumentException("Cannot execute invalid query");
+    }
     Native.exec(this.pointer, query.pointer, node);
   }