Optimize usage of "prepare for use" in draw and dispatch commands.

[DarioSamo]

Prepare for use is a command that got added due to the D3D12 driver requiring a step to transition resources to their required states, meaning the function needed to be called no matter what.

Due to how the function was written to share the loop used for validation (which does not get compiled into release games), this means that command was added and serialized into the render graph for every draw call even if the API did not require it at all.

Upon testing Nuku Warriors I found the command being called 72K times per frame on the Vulkan backend despite being a noop in that API. Furthermore, this path will also be skipped when #91769 is merged and the driver reports support for enhanced barriers.

I've not measured the performance differential but it is likely the CPU times can only improve with this change as it goes from doing something that was unnecessary to doing nothing.

[clayjohn]

Looks good to me

[akien-mga]

Thanks!

[Calinou]

For future reference, I benchmarked this change on https://github.com/godotengine/godot-benchmarks' Bunnymark 2D benchmarks with --print-fps, which are notoriously CPU-bound on my machine:

Benchmark	Before	After (this PR)
rendering/bunnymark/bunnymark_canvasitem_draw_api_5000	810 FPS (1.23 mspf)	830 FPS (1.20 mspf)
rendering/bunnymark/bunnymark_canvasitem_draw_api_10000	413 FPS (2.42 mspf)	428 FPS (2.33 mspf)
rendering/bunnymark/bunnymark_canvasitem_draw_api_20000	216 FPS (4.62 mspf)	220 FPS (4.54 mspf)
rendering/bunnymark/bunnymark_meshinstance2d_5000	527 FPS (1.89 mspf)	532 FPS (1.87 mspf)
rendering/bunnymark/bunnymark_meshinstance2d_10000	264 FPS (3.78 mspf)	266 FPS (3.75 mspf)
rendering/bunnymark/bunnymark_meshinstance2d_20000	133 FPS (7.51 mspf)	134 FPS (7.46 mspf)
rendering/bunnymark/bunnymark_sprite2d_5000	566 FPS (1.76 mspf)	569 FPS (1.75 mspf)
rendering/bunnymark/bunnymark_sprite2d_10000	278 FPS (3.59 mspf)	285 FPS (3.50 mspf)
rendering/bunnymark/bunnymark_sprite2d_20000	136 FPS (7.35 mspf)	141 FPS (7.09 mspf)

PC specifications

• CPU: Intel Core i9-13900K
• GPU: NVIDIA GeForce RTX 4090
• RAM: 64 GB (2×32 GB DDR5-5800 C30)
• SSD: Solidigm P44 Pro 2 TB
• OS: Linux (Fedora 39)