Make tests less noisy (#12463)

When running the tests for linux, I found a lot of benign errors getting
logged. This PR cuts down some of the noise from unnecessary workspace
serialization and SVG renders

Release Notes:

- N/A

crates/assets/src/assets.rs

@@ -16,9 +16,9 @@ use rust_embed::RustEmbed;
 pub struct Assets;
 
 impl AssetSource for Assets {
-    fn load(&self, path: &str) -> Result<std::borrow::Cow<'static, [u8]>> {
+    fn load(&self, path: &str) -> Result<Option<std::borrow::Cow<'static, [u8]>>> {
         Self::get(path)
-            .map(|f| f.data)
+            .map(|f| Some(f.data))
             .ok_or_else(|| anyhow!("could not find asset at path \"{}\"", path))
     }
 
@@ -42,7 +42,10 @@ impl Assets {
         let mut embedded_fonts = Vec::new();
         for font_path in font_paths {
             if font_path.ends_with(".ttf") {
-                let font_bytes = cx.asset_source().load(&font_path)?;
+                let font_bytes = cx
+                    .asset_source()
+                    .load(&font_path)?
+                    .expect("Assets should never return None");
                 embedded_fonts.push(font_bytes);
             }
         }