Remove cyclic dependency of egui_demo_lib on itself

crates/egui_demo_lib/Cargo.toml

@@ -55,9 +55,6 @@ serde = { workspace = true, optional = true }
 
 
 [dev-dependencies]
-# when running tests we always want to use the `chrono` feature
-egui_demo_lib = { workspace = true, features = ["chrono"] }
-
 criterion.workspace = true
 egui_kittest = { workspace = true, features = ["wgpu", "snapshot"] }
 wgpu = { workspace = true, features = ["metal"] }

crates/egui_demo_lib/src/demo/widget_gallery.rs

@@ -286,6 +286,7 @@ fn doc_link_label_with_crate<'a>(
     }
 }
 
+#[cfg(feature = "chrono")]
 #[cfg(test)]
 mod tests {
     use super::*;