fix(core): fs deps

viz-core/Cargo.toml

@@ -38,7 +38,7 @@ query = ["dep:serde", "dep:serde_urlencoded"]
 multipart = ["dep:form-data"]
 websocket = ["dep:tokio-tungstenite", "tokio/rt"]
 sse = ["dep:tokio-stream", "tokio/time"]
-fs = ["dep:tokio-util", "tokio/fs"]
+fs = ["tokio-util/io", "tokio/fs"]
 
 cookie = ["dep:cookie"]
 cookie-private = ["cookie", "cookie?/private"]