fix: optimization: PVS-Studio warning V832

It's better to use '= default;' syntax instead of empty constructor and destructor body.
Using '= default;' can help the compiler generate more optimal code.

Reported by: PVS-Studio

Signed-off-by: Vyacheslav Ivanov <islavaivanov76@gmail.com>

src/content/Content.cpp

@@ -46,8 +46,7 @@ Content::Content(
     }
 }
 
-Content::~Content() {
-}
+Content::~Content() = default;
 
 const rigging::SkeletonConfig* Content::getSkeleton(const std::string& id) const {
     auto found = skeletons.find(id);