Style: Remove inconsistently used @author docstrings

Each file in Godot has had multiple contributors who co-authored it over the
years, and the information of who was the original person to create that file
is not very relevant, especially when used so inconsistently.

`git blame` is a much better way to know who initially authored or later
modified a given chunk of code, and most IDEs now have good integration to
show this information.

servers/navigation_server_3d.cpp

@@ -28,10 +28,6 @@
 /* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                */
 /*************************************************************************/
 
-/**
-	@author AndreaCatania
-*/
-
 #include "navigation_server_3d.h"
 
 NavigationServer3D *NavigationServer3D::singleton = nullptr;