[Release] bump v0.4.5.post3

[zhyncs]

The SGLang team is pleased to announce the release of v0.4.5.post3. Enjoy!

pip install "sglang[all]>=0.4.5.post3"

#5611 (comment)

[zhyncs]

# warmup DeepGEMM
SGL_ENABLE_JIT_DEEPGEMM=1 python3 -m sglang.compile_deep_gemm --model deepseek-ai/DeepSeek-V3 --tp 8 --trust-remote-code
# launch server
SGL_ENABLE_JIT_DEEPGEMM=1 python3 -m sglang.launch_server --model-path deepseek-ai/DeepSeek-V3 --tp 8 --trust-remote-code