Remove the old `execute` module

sparse_strips/vello_common/src/execute.rs

diff --git a/sparse_strips/vello_common/src/execute.rs b/sparse_strips/vello_common/src/execute.rs
deleted file mode 100644
index cac9043..0000000
--- a/sparse_strips/vello_common/src/execute.rs
+++ /dev/null
@@ -1,54 +0,0 @@
-// Copyright 2025 the Vello Authors
-// SPDX-License-Identifier: Apache-2.0 OR MIT
-
-//! Different execution modes for kernels.
-
-#[derive(Copy, Clone, Debug)]
-/// The execution mode used for the rendering process.
-pub enum ExecutionMode {
-    /// Only use scalar execution. This is recommended if you want to have
-    /// consistent results across different platforms and want to avoid unsafe code,
-    /// and is the only option if you disabled the `simd` feature. Performance will be
-    /// worse, though.
-    Scalar,
-    /// Select the best execution mode according to what is available on the host system.
-    /// This is the recommended option for highest performance.
-    #[cfg(feature = "simd")]
-    Auto,
-    /// Force the usage of neon SIMD instructions. This will lead to panics in case
-    /// the CPU doesn't support the target feature `neon`.
-    #[cfg(all(target_arch = "aarch64", feature = "simd"))]
-    Neon,
-    /// Force the usage of AVX2 SIMD instructions. This will lead to panics in case
-    /// the CPU doesn't support the target features `avx2` and `fma`.
-    #[cfg(all(target_arch = "x86_64", feature = "simd"))]
-    Avx2,
-}
-
-#[cfg(feature = "simd")]
-impl Default for ExecutionMode {
-    fn default() -> Self {
-        Self::Auto
-    }
-}
-
-#[cfg(not(feature = "simd"))]
-impl Default for ExecutionMode {
-    fn default() -> Self {
-        Self::Scalar
-    }
-}
-
-/// Scalar execution mode.
-#[derive(Debug)]
-pub struct Scalar;
-
-#[cfg(all(target_arch = "aarch64", feature = "simd"))]
-#[derive(Debug)]
-/// Execute using NEON intrinsics.
-pub struct Neon;
-
-#[cfg(all(target_arch = "x86_64", feature = "simd"))]
-#[derive(Debug)]
-/// Execute using AVX2 intrinsics.
-pub struct Avx2;

sparse_strips/vello_common/src/lib.rs

diff --git a/sparse_strips/vello_common/src/lib.rs b/sparse_strips/vello_common/src/lib.rs
index 56ca04c..9b2aa28 100644
--- a/sparse_strips/vello_common/src/lib.rs
+++ b/sparse_strips/vello_common/src/lib.rs
@@ -66,7 +66,6 @@
 #[cfg(feature = "text")]
 pub mod colr;
 pub mod encode;
-pub mod execute;
 pub mod flatten;
 pub(crate) mod flatten_simd;
 #[cfg(feature = "text")]