fix: build Unity Catalog crate without DataFusion

[linhr]

Description

I was trying to build the deltalake-catalog-unity crate without the datafusion feature. Here is the command I used:

cargo build -p deltalake-catalog-unity --no-default-features --features "aws"

I encountered the following error.

error[E0432]: unresolved import `datafusion_common`
  --> crates/catalog-unity/src/lib.rs:10:5
   |
10 | use datafusion_common::DataFusionError;
   |     ^^^^^^^^^^^^^^^^^ use of unresolved module or unlinked crate `datafusion_common`
   |
   = help: if you wanted to use a crate named `datafusion_common`, use `cargo add datafusion_common` to add it to your `Cargo.toml`

For more information about this error, try `rustc --explain E0432`.
error: could not compile `deltalake-catalog-unity` (lib) due to 1 previous error

This PR fixes the build error.

Related Issue(s)

N/A

Documentation

N/A