Fixes a bunch of clippy warnings, adds clippy to CI

src/static_data/natures.rs

@@ -68,7 +68,7 @@ impl NatureLibrary {
         for kv in &self.map {
             // As natures can't be copied, and should always be the same reference as the value
             // in the map, we just compare by reference.
-            if (kv.1 as *const Nature) == (nature as *const Nature) {
+            if std::ptr::eq(kv.1, nature) {
                 return kv.0.clone();
             }
         }