Enable parquet parallel scans by default

[alamb]

Is your feature request related to a problem or challenge? Please describe what you are trying to do.
@korowa added a feature to automatically repartition individual files in #5057 however it is behind a feature flag that defaults to false

Describe the solution you'd like
Turn on file level repartitioning that was added in #5057 by default so that all users of DataFusion can benefit

Describe alternatives you've considered
A clear and concise description of any alternative solutions or features you've considered.

Additional context
Add any other context or screenshots about the feature request here.