Automatically install rust toolchain for CI

enkou-shaders-tests/build.rs

@@ -9,9 +9,11 @@ pub fn main() -> anyhow::Result<()> {
         .copied()
         .collect::<PathBuf>();
 
-    let install = Install::from_shader_crate(crate_path.clone())
+    let mut install = Install::from_shader_crate(crate_path.clone());
-        .within_build_script()
+    install.build_script = true;
-        .run()?;
+    install.auto_install_rust_toolchain = true;
+    let install = install.run()?;
+
     let mut builder = install.to_spirv_builder(crate_path, "spirv-unknown-vulkan1.3");
     builder.build_script.defaults = true;
     builder.shader_panic_strategy = ShaderPanicStrategy::SilentExit;