Bump version to v0.6.1 (vllm-project#8379)

Bump version to v0.6.0 (vllm-project#8166)

Bump version to v0.5.5 (vllm-project#7823)

bump version to v0.5.4 (vllm-project#7139)

Bump version to v0.5.3 (vllm-project#6674)

Bump version to 0.5.3.post1 (vllm-project#6696)

[misc][distributed] fix pp missing layer condition (vllm-project#6446)

[Docs] Fix readthedocs for tag build (vllm-project#6158)

Add `cuda_device_count_stateless` (vllm-project#5473)

[Doc] add common case for long waiting time (vllm-project#5430)