Disable reference-types since Wizer doesn't support them (#785)

.cargo/config.toml

@@ -2,8 +2,15 @@
 # Cargo doesn't read directives in individual crates when invoking build
 # commands from the workspace root, hence adding it at the workspace root.
 # https://doc.rust-lang.org/cargo/reference/config.html
+# Disable reference-types since Wizer (as of version 7.0.0) does not support
+# reference-types.
 [target.wasm32-wasi]
-rustflags = ["-C", "target-feature=+simd128"]
+rustflags = [
+    "-C",
+    "target-feature=+simd128",
+    "-C",
+    "target-feature=-reference-types",
+]
 
 # We want to ensure that all the MSVC dependencies are statically resolved and
 # included in the final CLI binary.