GH-105481: Mark more files as generated (GH-107598)

Author: brandtbucher

.gitattributes

@@ -72,9 +72,11 @@ Doc/library/token-list.inc                          generated
 Include/internal/pycore_ast.h                       generated
 Include/internal/pycore_ast_state.h                 generated
 Include/internal/pycore_opcode.h                    generated
+Include/internal/pycore_opcode_metadata.h           generated
 Include/internal/pycore_*_generated.h               generated
 Include/opcode.h                                    generated
 Include/token.h                                     generated
+Lib/_opcode_metadata.py                             generated
 Lib/keyword.py                                      generated
 Lib/test/levenshtein_examples.json                  generated
 Lib/test/test_stable_abi_ctypes.py                  generated