add Debug for ptr types (#13498)

# Objective

- I wanted to store a Ptr in a struct of mine that has a
`#[derive(Debug)]` and I noticed that the Ptrs don't implement Debug,
even though the underlying `NonNull<u8>` does

## Solution

- Add `#[derive(Debug)]`

crates/bevy_ptr/src/lib.rs

@@ -155,7 +155,7 @@ impl<'a, T: ?Sized> From<&'a mut T> for ConstNonNull<T> {
 ///
 /// It may be helpful to think of this type as similar to `&'a dyn Any` but without
 /// the metadata and able to point to data that does not correspond to a Rust type.
-#[derive(Copy, Clone)]
+#[derive(Copy, Clone, Debug)]
 #[repr(transparent)]
 pub struct Ptr<'a, A: IsAligned = Aligned>(NonNull<u8>, PhantomData<(&'a u8, A)>);
 
@@ -170,6 +170,7 @@ pub struct Ptr<'a, A: IsAligned = Aligned>(NonNull<u8>, PhantomData<(&'a u8, A)>
 ///
 /// It may be helpful to think of this type as similar to `&'a mut dyn Any` but without
 /// the metadata and able to point to data that does not correspond to a Rust type.
+#[derive(Debug)]
 #[repr(transparent)]
 pub struct PtrMut<'a, A: IsAligned = Aligned>(NonNull<u8>, PhantomData<(&'a mut u8, A)>);
 
@@ -188,6 +189,7 @@ pub struct PtrMut<'a, A: IsAligned = Aligned>(NonNull<u8>, PhantomData<(&'a mut
 ///
 /// It may be helpful to think of this type as similar to `&'a mut ManuallyDrop<dyn Any>` but
 /// without the metadata and able to point to data that does not correspond to a Rust type.
+#[derive(Debug)]
 #[repr(transparent)]
 pub struct OwningPtr<'a, A: IsAligned = Aligned>(NonNull<u8>, PhantomData<(&'a mut u8, A)>);