sparse set: I don't even read my own comments sometimes :)

src/entt/entity/sparse_set.hpp

@@ -165,7 +165,7 @@ class basic_sparse_set {
     static constexpr auto max_size = static_cast<std::size_t>(traits_type::to_entity(null));
 
     // it could be auto but gcc complains and emits a warning due to a false positive
-    [[nodiscard]] auto policy_to_head() const noexcept {
+    [[nodiscard]] std::size_t policy_to_head() const noexcept {
         return static_cast<size_type>(max_size * static_cast<decltype(max_size)>(mode != deletion_policy::swap_only));
     }