ui_macros: Remove DerivePathStr macro (#30862)

This PR removes the `DerivePathStr` macro, as it is no longer used.

Also removes the `PathStaticStr` macro from `gpui_macros`, which was
also unused.

Release Notes:

- N/A

crates/ui/src/tests.rs

@@ -1 +0,0 @@
-mod path_str;

crates/ui/src/tests/path_str.rs

@@ -1,35 +0,0 @@
-// We need to test [ui_macros::DerivePathStr] here as we can't invoke it
-// in the `ui_macros` crate.
-#[cfg(test)]
-mod tests {
-    use strum::EnumString;
-    use ui_macros::{DerivePathStr, path_str};
-
-    #[test]
-    fn test_derive_path_str_with_prefix() {
-        #[derive(Debug, EnumString, DerivePathStr)]
-        #[strum(serialize_all = "snake_case")]
-        #[path_str(prefix = "test_prefix")]
-        enum SomeAsset {
-            FooBar,
-            Baz,
-        }
-
-        assert_eq!(SomeAsset::FooBar.path(), "test_prefix/foo_bar");
-        assert_eq!(SomeAsset::Baz.path(), "test_prefix/baz");
-    }
-
-    #[test]
-    fn test_derive_path_str_with_prefix_and_suffix() {
-        #[derive(Debug, EnumString, DerivePathStr)]
-        #[strum(serialize_all = "snake_case")]
-        #[path_str(prefix = "test_prefix", suffix = ".svg")]
-        enum SomeAsset {
-            FooBar,
-            Baz,
-        }
-
-        assert_eq!(SomeAsset::FooBar.path(), "test_prefix/foo_bar.svg");
-        assert_eq!(SomeAsset::Baz.path(), "test_prefix/baz.svg");
-    }
-}

crates/ui/src/ui.rs

@@ -11,7 +11,6 @@ pub mod component_prelude;
 mod components;
 pub mod prelude;
 mod styles;
-mod tests;
 mod traits;
 pub mod utils;