Use unanchored clang-format version check

`clang-format -version` installed with apt on Ubuntu reports `Ubuntu clang-format version 11.0.0-2~ubuntu20.04.1`, so we need an unanchored search here.

(Equivalent to rapidsai/cuml@dafcd6f.)

cpp/scripts/run-clang-format.py

@@ -1,4 +1,4 @@
-# Copyright (c) 2020, NVIDIA CORPORATION.
+# Copyright (c) 2020-2022, NVIDIA CORPORATION.
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
@@ -64,7 +64,7 @@ def parse_args():
         args.dstdir = tempfile.mkdtemp()
     ret = subprocess.check_output("%s --version" % args.exe, shell=True)
     ret = ret.decode("utf-8")
-    version = VERSION_REGEX.match(ret)
+    version = VERSION_REGEX.search(ret)
     if version is None:
         raise Exception("Failed to figure out clang-format version!")
     version = version.group(1)