python3-pip: remove unneeded reproducible.patch

python3-pip: remove unneeded reproducible.patch

Since "python_pep517: use installer instead of pip" pip is no longer
used in builds, and therefore doesn't need to behave reproducibly.

I have submitted the patch upstream; upstream have suggested that the
way it had been used previously is non-reproducible by design, and
if pip is again brought into builds in the future, we should use
specific options for reproducibility:

https://github.com/pypa/pip/issues/11424

Signed-off-by: Alexander Kanavin <alex@linutronix.de>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>