scripts/kernel-doc.py: properly handle KBUILD_BUILD_TIMESTAMP

The logic that handles KBUILD_BUILD_TIMESTAMP is wrong, and adds
a dependency of a third party module (dateutil).

Fix it.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Link: https://lore.kernel.org/r/ffc70a1b741b010365ed82f31611018f24f91ce7.1744106242.git.mchehab+huawei@kernel.org

scripts/lib/kdoc/kdoc_files.py

@@ -13,9 +13,6 @@ import logging
 import os
 import re
 import sys
-from datetime import datetime
-
-from dateutil import tz
 
 from kdoc_parser import KernelDoc
 from kdoc_output import OutputFormat
@@ -137,12 +134,6 @@ class KernelFiles():
         if out_style is None:
             out_style = OutputFormat()
 
-        dt = datetime.now()
-        if os.environ.get("KBUILD_BUILD_TIMESTAMP", None):
-            # use UTC TZ
-            to_zone = tz.gettz('UTC')
-            dt = dt.astimezone(to_zone)
-
         if not werror:
             kcflags = os.environ.get("KCFLAGS", None)
             if kcflags: