Remove self includes in some files

[blackbird806]

It seems that rendering_device.h is including himself, so I just removed that.

[akien-mga]

Good catch. I found a bunch more, so I'll amend this PR or make a new one to fix them all.

$ for file in $(find -type f -name "*.h" | sed -e "s,\./,," | sort); do res1=$(grep "^#include \"$file\"" $file); res2=$(grep "^#include \"$(basename $file)\"" $file); if [ ! -z "$res1" -o ! -z "$res2" ]; then echo -e "\n$file"; echo $res1 $res2; fi; done

modules/navigation/nav_agent.h
#include "nav_agent.h"

scene/resources/world_2d.h
#include "scene/resources/world_2d.h"

servers/rendering/rendering_device.h
#include "servers/rendering/rendering_device.h"

thirdparty/cvtt/ConvectionKernels_BC6H_IO.h
#include "ConvectionKernels_BC6H_IO.h"

thirdparty/d3d12ma/D3D12MemAlloc.h
#include "D3D12MemAlloc.h"

thirdparty/mbedtls/library/mps_trace.h
#include "mps_trace.h"

thirdparty/vulkan/vk_mem_alloc.h
#include "vk_mem_alloc.h" #include "vk_mem_alloc.h" #include "vk_mem_alloc.h" #include "vk_mem_alloc.h" #include "vk_mem_alloc.h" #include "vk_mem_alloc.h"

[akien-mga]

Thanks! And congrats for your first merged Godot contribution 🎉