Fix semantic conflict in vortex-file tests (#10731)

## Summary

Develop doesn't compile vortex-file's tests. #10533 added
`nested_empty_list_roundtrip`, which calls `ListArray::try_new` with
three arguments, but #10594 had already added a fourth, the execution
context. Both passed CI on their own. Since #10533 merged, the Rust
build, lint and test jobs fail on develop and on every PR.

## Changes

- `nested_empty_list_roundtrip` creates an execution context and passes
it to both `ListArray::try_new` calls, as
`nested_list_of_list_roundtrip` just above it already does.

## Testing

- `cargo nextest run -p vortex-file -E
'test(/nested_empty_list_roundtrip|nested_list_of_list_roundtrip/)'` (5
passed)
- `cargo clippy -p vortex-file --all-targets --all-features -- -D
warnings`
- `cargo +nightly-2026-09-10 fmt -p vortex-file --check`

Signed-off-by: Matt Katz <mhkatz97@gmail.com>

Author: mhk197

vortex-file/src/tests.rs

@@ -2047,13 +2047,16 @@ async fn nested_list_of_list_roundtrip() -> VortexResult<()> {
 #[tokio::test]
 #[cfg_attr(miri, ignore)]
 async fn nested_empty_list_roundtrip(#[case] validity: Validity) -> VortexResult<()> {
+    let mut ctx = SESSION.create_execution_ctx();
     let inner = ListArray::try_new(
         PrimitiveArray::new::<i32>(buffer![], Validity::NonNullable).into_array(),
         buffer![0u32].into_array(),
         Validity::NonNullable,
+        &mut ctx,
     )?
     .into_array();
-    let outer = ListArray::try_new(inner, buffer![0u32, 0, 0].into_array(), validity)?.into_array();
+    let outer = ListArray::try_new(inner, buffer![0u32, 0, 0].into_array(), validity, &mut ctx)?
+        .into_array();
     let array = StructArray::from_fields(&[("nested", outer)])?.into_array();
 
     let result = write_read_roundtrip(array.clone()).await?;