fix(nvim-treesitter): use attribute instead of meta_item

Ref: tree-sitter/tree-sitter-rust#163

Author: mars90226

queries/rust/textobjects.scm

@@ -4,12 +4,12 @@
 
 (array_expression (_) @swappable)
 (arguments (_) @swappable)
+(attribute) @swappable
 (enum_variant) @swappable
 (field_declaration) @swappable
 (field_initializer_list (_) @swappable)
 (function_item) @swappable
 (match_arm) @swappable
-(meta_item) @swappable
 (ordered_field_declaration_list (_) @swappable)
 (parameters (_) @swappable)
 (use_list (_) @swappable)