Chore: remove unstable pipeline benchmark (#5512)

Signed-off-by: Connor Tsui <[email protected]>

Author: connortsui20

vortex/benches/pipeline.rs

@@ -794,6 +794,7 @@ fn compare_outputs(function_name: &str, expected: &[f32], actual: &[f32], expect
 // Benchmarks
 ////////////////////////////////////////////////////////////////////////////////////////////////////
 
+#[cfg(not(codspeed))]
 #[divan::bench(consts = BENCHMARK_SIZES, sample_size = SAMPLE_SIZE)]
 fn batch<const SIZE: usize>(bencher: Bencher) {
     let (input_data, mut buffers) = setup(SIZE);
@@ -813,6 +814,7 @@ fn batch<const SIZE: usize>(bencher: Bencher) {
     });
 }
 
+#[cfg(not(codspeed))]
 #[divan::bench(consts = BENCHMARK_SIZES, sample_size = SAMPLE_SIZE)]
 fn pipeline<const SIZE: usize>(bencher: Bencher) {
     let (input_data, mut buffers) = setup(SIZE);
@@ -831,6 +833,7 @@ fn pipeline<const SIZE: usize>(bencher: Bencher) {
     });
 }
 
+#[cfg(not(codspeed))]
 #[divan::bench(consts = BENCHMARK_SIZES, sample_size = SAMPLE_SIZE)]
 fn pipeline_extra_copy<const SIZE: usize>(bencher: Bencher) {
     let (input_data, mut buffers) = setup(SIZE);
@@ -850,6 +853,7 @@ fn pipeline_extra_copy<const SIZE: usize>(bencher: Bencher) {
     });
 }
 
+#[cfg(not(codspeed))]
 #[divan::bench(consts = BENCHMARK_SIZES, sample_size = SAMPLE_SIZE)]
 fn in_place_batch<const SIZE: usize>(bencher: Bencher) {
     let (input_data, mut buffers) = setup(SIZE);
@@ -866,6 +870,7 @@ fn in_place_batch<const SIZE: usize>(bencher: Bencher) {
     });
 }
 
+#[cfg(not(codspeed))]
 #[divan::bench(consts = BENCHMARK_SIZES, sample_size = SAMPLE_SIZE)]
 fn in_place_pipeline<const SIZE: usize>(bencher: Bencher) {
     let (input_data, mut buffers) = setup(SIZE);
@@ -887,6 +892,7 @@ fn in_place_pipeline<const SIZE: usize>(bencher: Bencher) {
 // These benchmarks verify that all decompression strategies produce identical
 // and correct results. They run with smaller sizes for quick verification.
 
+#[cfg(not(codspeed))]
 #[divan::bench(consts = VERIFICATION_SIZES)]
 fn verify_all_methods<const SIZE: usize>(bencher: Bencher) {
     bencher