[clang-tidy][clang-tidy-diff.py] Change shebang from python to python3

diff --git a/clang-tools-extra/clang-tidy/tool/clang-tidy-diff.py b/clang-tools-extra/clang-tidy/tool/clang-tidy-diff.py
index 45c28d9..c8a83bd 100755 (executable)
--- a/clang-tools-extra/clang-tidy/tool/clang-tidy-diff.py
+++ b/clang-tools-extra/clang-tidy/tool/clang-tidy-diff.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 #
 # ===- clang-tidy-diff.py - ClangTidy Diff Checker -----------*- python -*--===#
 #