Ignore test by default

sparse_strips/vello_hybrid/src/render/webgl.rs

diff --git a/sparse_strips/vello_hybrid/src/render/webgl.rs b/sparse_strips/vello_hybrid/src/render/webgl.rs
index 8ee19aa..da0ebd7 100644
--- a/sparse_strips/vello_hybrid/src/render/webgl.rs
+++ b/sparse_strips/vello_hybrid/src/render/webgl.rs
@@ -515,6 +515,9 @@
 
     #[cfg(feature = "probe")]
     fn probe_inner(&mut self) -> Result<WebGlPendingProbe, RenderError> {
+        // IMPORTANT NOTE: When making any changes to the probe, make sure to
+        // unignore and rerun the "webgl_probe_succeeds" test locally.
+
         let _state_guard = WebGlStateGuard::with_config(
             &self.gl,
             WebGlStateConfig {

sparse_strips/vello_sparse_tests/tests/wasm_binary_invariants.rs

diff --git a/sparse_strips/vello_sparse_tests/tests/wasm_binary_invariants.rs b/sparse_strips/vello_sparse_tests/tests/wasm_binary_invariants.rs
index 92c3bb7..8cf15ed 100644
--- a/sparse_strips/vello_sparse_tests/tests/wasm_binary_invariants.rs
+++ b/sparse_strips/vello_sparse_tests/tests/wasm_binary_invariants.rs
@@ -40,6 +40,8 @@
     );
 }
 
+// This test is ignored by default due to flakiness in Github CI.
+#[ignore]
 #[cfg(feature = "webgl")]
 #[wasm_bindgen_test]
 async fn webgl_probe_succeeds() {