[Z-Image] various small changes, Z-Image transformer tests, etc. (#12… #5151

Job	Run time
Setup Torch Pipelines CUDA Slow Tests Matrix	53s
PyTorch Compile CUDA tests	3m 27s
Torch CUDA Tests (single_file)	46s
Torch CUDA Tests (lora)	14m 24s
Torch CUDA Tests (others)	3m 18s
Torch CUDA Tests (schedulers)	5m 22s
Torch CUDA Tests (models)	13m 37s
PyTorch xformers CUDA tests	8m 49s
Examples PyTorch CUDA tests on Ubuntu	46m 58s
Torch Pipelines CUDA Tests (controlnet_flux)	3m 28s
Torch Pipelines CUDA Tests (ddpm)	2m 49s
Torch Pipelines CUDA Tests (flux)	5m 0s
Torch Pipelines CUDA Tests (cogvideo)	4m 27s
Torch Pipelines CUDA Tests (flux2)	4m 32s
Torch Pipelines CUDA Tests (pixart_alpha)	1m 0s
Torch Pipelines CUDA Tests (stable_diffusion)	4m 30s
Torch Pipelines CUDA Tests (ip_adapters)	39s
Torch Pipelines CUDA Tests (controlnet)	13m 15s
Torch Pipelines CUDA Tests (latent_consistency_models)	1m 35s
Torch Pipelines CUDA Tests (controlnet_sd3)	3m 29s
Torch Pipelines CUDA Tests (ltx)	1m 58s
Torch Pipelines CUDA Tests (sana)	6m 38s
Torch Pipelines CUDA Tests (marigold)	1m 52s
Torch Pipelines CUDA Tests (stable_diffusion_2)	3m 5s
Torch Pipelines CUDA Tests (hidream_image)	3m 30s
Torch Pipelines CUDA Tests (hunyuandit)	1m 6s
Torch Pipelines CUDA Tests (qwenimage)	9m 11s
Torch Pipelines CUDA Tests (stable_diffusion_3)	1m 28s
Torch Pipelines CUDA Tests (stable_diffusion_xl)	7m 37s
Torch Pipelines CUDA Tests (z_image)	1m 18s
Torch Pipelines CUDA Tests (wan)	4m 57s
Torch Pipelines CUDA Tests (stable_video_diffusion)	3m 16s
	3h 8m 14s

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