Fix: Actually update LMCache to main branch (previous edit failed)

vllm/Dockerfile

@@ -94,9 +94,10 @@ RUN cd flashinfer && \
     uv build --wheel --no-build-isolation -o /wheels
 
 FROM build-base AS build-lmcache
-ARG LMCACHE_REF=v0.3.7
-RUN git clone https://github.com/LMCache/LMCache.git -b ${LMCACHE_REF} && \
+# Bleeding edge: build from main branch (v0.4.2+)
+RUN git clone https://github.com/LMCache/LMCache.git && \
     cd LMCache && \
+    git checkout main && \
 # PyTorch version is dated in LMCache
     sed -i '/torch/d' pyproject.toml && \
     uv pip install setuptools_scm && \