glib-macros: Remove unused imports from Properties doc test

glib-macros/src/lib.rs

@@ -883,7 +883,7 @@
 ///
 /// ## Using Rust keywords as property names
 /// You might hit a roadblock when declaring properties with this macro because you want to use a name that happens to be a Rust keyword. This may happen with names like `loop`, which is a pretty common name when creating things like animation handlers.
 /// To use those names, you can make use of the raw identifier feature of Rust. Simply prefix the identifier name with `r#` in the struct declaration. Internally, those `r#`s are stripped so you can use its expected name in [`ObjectExt::property`] or within GtkBuilder template files.
 ///
 /// # Generated methods
 /// The following methods are generated on the wrapper type specified on `#[properties(wrapper_type = ...)]`:
@@ -935,8 +935,6 @@
 /// # Example
 /// ```
 /// use std::cell::RefCell;
-/// use std::marker::PhantomData;
-/// use std::sync::Mutex;
 /// use glib::prelude::*;
 /// use glib::subclass::prelude::*;
 /// use glib_macros::Properties;