package/python-avro: fix capitalizations of Parse

python-avro 1.11.0 deprecated schema.Parse [1] and actually error
out when used.

Fixes:
https://gitlab.com/buildroot.org/buildroot/-/jobs/2429013770

[1] https://github.com/apache/avro/commit/3e79dfec8461fb0157f068cff7ba24be8cdfa9d8



Signed-off-by: Romain Naour <romain.naour@gmail.com>
Signed-off-by: Yann E. MORIN <yann.morin.1998@free.fr>