spirv-tools: Update merged patch to backport status

Patch 0001-update_build_version.py-support-an-envvar-to-force-t.patch
was merged here: https://github.com/KhronosGroup/SPIRV-Tools/commit/bc4060ed274ad9749c20daced96d6f0518d6418e



Signed-off-by: Yoann Congal <yoann.congal@smile.fr>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>