Remove unnecessary windows.rs file (#7277)

# Objective
Accidentally re-added this old file at some point during the Windows as Entities PR apparently

## Solution
Removed the file, its unused

crates/bevy_window/src/windows.rs

@@ -1,88 +0,0 @@
-use super::{Window, WindowId};
-use bevy_ecs::prelude::Resource;
-use bevy_utils::HashMap;
-
-/// A collection of [`Window`]s with unique [`WindowId`]s.
-#[derive(Debug, Default, Resource)]
-pub struct Windows {
-    windows: HashMap<WindowId, Window>,
-}
-
-impl Windows {
-    /// Add the provided [`Window`] to the [`Windows`] resource.
-    pub fn add(&mut self, window: Window) {
-        self.windows.insert(window.id(), window);
-    }
-
-    /// Get a reference to the [`Window`] of `id`.
-    pub fn get(&self, id: WindowId) -> Option<&Window> {
-        self.windows.get(&id)
-    }
-
-    /// Get a mutable reference to the provided [`WindowId`].
-    pub fn get_mut(&mut self, id: WindowId) -> Option<&mut Window> {
-        self.windows.get_mut(&id)
-    }
-
-    /// Get a reference to the primary [`Window`].
-    pub fn get_primary(&self) -> Option<&Window> {
-        self.get(WindowId::primary())
-    }
-
-    /// Get a reference to the primary [`Window`].
-    ///
-    /// # Panics
-    ///
-    /// Panics if the primary window does not exist in [`Windows`].
-    pub fn primary(&self) -> &Window {
-        self.get_primary().expect("Primary window does not exist")
-    }
-
-    /// Get a mutable reference to the primary [`Window`].
-    pub fn get_primary_mut(&mut self) -> Option<&mut Window> {
-        self.get_mut(WindowId::primary())
-    }
-
-    /// Get a mutable reference to the primary [`Window`].
-    ///
-    /// # Panics
-    ///
-    /// Panics if the primary window does not exist in [`Windows`].
-    pub fn primary_mut(&mut self) -> &mut Window {
-        self.get_primary_mut()
-            .expect("Primary window does not exist")
-    }
-
-    /// Get a reference to the focused [`Window`].
-    pub fn get_focused(&self) -> Option<&Window> {
-        self.windows.values().find(|window| window.is_focused())
-    }
-
-    /// Get a mutable reference to the focused [`Window`].
-    pub fn get_focused_mut(&mut self) -> Option<&mut Window> {
-        self.windows.values_mut().find(|window| window.is_focused())
-    }
-
-    /// Returns the scale factor for the [`Window`] of `id`, or `1.0` if the window does not exist.
-    pub fn scale_factor(&self, id: WindowId) -> f64 {
-        if let Some(window) = self.get(id) {
-            window.scale_factor()
-        } else {
-            1.0
-        }
-    }
-
-    /// An iterator over all registered [`Window`]s.
-    pub fn iter(&self) -> impl Iterator<Item = &Window> {
-        self.windows.values()
-    }
-
-    /// A mutable iterator over all registered [`Window`]s.
-    pub fn iter_mut(&mut self) -> impl Iterator<Item = &mut Window> {
-        self.windows.values_mut()
-    }
-
-    pub fn remove(&mut self, id: WindowId) -> Option<Window> {
-        self.windows.remove(&id)
-    }
-}