Un-fork `datafusion`

[crepererum]

What

Remove this crates.io override:

datafusion-udf-wasm/Cargo.toml

Lines 54 to 57 in a99b13a

	# use same DataFusion fork as InfluxDB
	# See https://github.com/influxdata/arrow-datafusion/pull/72
	datafusion-common = { git = "https://github.com/influxdata/arrow-datafusion.git", rev = "8347a71f62d4fef8d37548f22b93877170039357" }
	datafusion-expr = { git = "https://github.com/influxdata/arrow-datafusion.git", rev = "8347a71f62d4fef8d37548f22b93877170039357" }

Why

If you want to build your own Rust guests, it would be nice if you wouldn't need a patched datafusion.

How

Wait for the first release that includes influxdata/arrow-datafusion#72 and then upgrade DataFusion.