bevy_derive: Fix #[deref] breaking other attributes (bevyengine#9551)

# Objective

Fixes bevyengine#9550

## Solution

Removes a check that asserts that _all_ attribute metas are path-only,
rather than just the `#[deref]` attribute itself.

---

## Changelog

- Fixes an issue where deriving `Deref` with `#[deref]` on a field
causes other attributes to sometimes result in a compile error

---------

Co-authored-by: François <[email protected]>

crates/bevy_derive/src/derefs.rs

@@ -68,10 +68,12 @@ fn get_deref_field(ast: &DeriveInput, is_mut: bool) -> syn::Result<(Member, &Typ
             let mut selected_field: Option<(Member, &Type)> = None;
             for (index, field) in data_struct.fields.iter().enumerate() {
                 for attr in &field.attrs {
-                    if !attr.meta.require_path_only()?.is_ident(DEREF_ATTR) {
+                    if !attr.meta.path().is_ident(DEREF_ATTR) {
                         continue;
                     }
 
+                    attr.meta.require_path_only()?;
+
                     if selected_field.is_some() {
                         return Err(syn::Error::new_spanned(
                             attr,

crates/bevy_macros_compile_fail_tests/tests/deref_derive/multiple_fields.pass.rs

@@ -5,18 +5,24 @@ struct TupleStruct(usize, #[deref] String);
 
 #[derive(Deref)]
 struct Struct {
+    // Works with other attributes
+    #[cfg(test)]
     foo: usize,
     #[deref]
     bar: String,
+    /// Also works with doc comments.
+    baz: i32,
 }
 
 fn main() {
     let value = TupleStruct(123, "Hello world!".to_string());
     let _: &String = &*value;
 
     let value = Struct {
+        #[cfg(test)]
         foo: 123,
         bar: "Hello world!".to_string(),
+        baz: 321,
     };
     let _: &String = &*value;
 }