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>
(cherry picked from commit 5468cf1095f236fc01f16015a7cf6cfeee69fe55)
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

support/testing/tests/package/sample_python_avro.py

@@ -1,8 +1,8 @@
 from io import BytesIO
-from avro.schema import Parse
+from avro.schema import parse
 from avro.io import DatumReader, BinaryDecoder
 
-schema = Parse("""{
+schema = parse("""{
 "namespace": "org.buildroot.package.python_avro",
 "type": "record",
 "name": "Developer",