Drawable Renderer (#1570), CI warnings

include/mbgl/renderer/layer_group.hpp

@@ -39,7 +39,7 @@ protected:
 public:
     LayerGroupBase(const LayerGroupBase&) = delete;
     LayerGroupBase& operator=(const LayerGroupBase&) = delete;
-    virtual ~LayerGroupBase() = default;
+    ~LayerGroupBase() override = default;
 
     /// Whether the drawables should be drawn
     bool getEnabled() const { return enabled; }

src/mbgl/renderer/possibly_evaluated_property_value.hpp

@@ -25,7 +25,7 @@ public:
 
     std::optional<T> constant() const {
         return value.match([&](const T& t) { return std::optional<T>(t); },
-                           [&](const auto&) { return std::optional<T>(); });
+                           [&](const auto&) { return std::optional<T>{}; });
     }
 
     T constantOr(const T& t) const { return constant().value_or(t); }