Fix fuzzer

Signed-off-by: Adam Gutglick <adam@spiraldb.com>

Author: AdamGS

fuzz/src/array/fill_null.rs

@@ -44,6 +44,7 @@ pub fn fill_null_canonical_array(
         | Canonical::List(_)
         | Canonical::FixedSizeList(_)
         | Canonical::Extension(_) => canonical.into_array().fill_null(fill_value.clone())?,
+        Canonical::Variant(_) => unreachable!("Variant arrays are not fuzzed"),
     })
 }
 

fuzz/src/array/mask.rs

@@ -136,6 +136,7 @@ pub fn mask_canonical_array(canonical: Canonical, mask: &Mask) -> VortexResult<A
                 .with_nullability(masked_storage.dtype().nullability());
             ExtensionArray::new(ext_dtype, masked_storage).into_array()
         }
+        Canonical::Variant(_) => unreachable!("Variant arrays are not fuzzed"),
     })
 }
 

fuzz/src/array/scalar_at.rs

@@ -95,5 +95,6 @@ pub fn scalar_at_canonical_array(canonical: Canonical, index: usize) -> VortexRe
                 scalar_at_canonical_array(array.storage_array().to_canonical()?, index)?;
             Scalar::extension_ref(array.ext_dtype().clone(), storage_scalar)
         }
+        Canonical::Variant(_) => unreachable!("Variant arrays are not fuzzed"),
     })
 }