[Docs][Python][Parquet] Update parquet default version text in parquet.rst

[tadeja]

Describe the bug, including details regarding any error messages, version, and platform.

Doc page https://arrow.apache.org/docs/python/parquet.html still mentions 'default version 1.0' instead of current default version 2.6 for pyarrow.parquet.write_table. This needs a non-minor pr update as per past discussion in #37227 (comment).

Component(s)

Documentation, Python, Parquet

[AlenkaF]

Issue resolved by pull request 50228
#50228