[CI/Build][CPU] Fix flaky CI image build failure and unexpected warnings (#44852)

Signed-off-by: jiang1.li <jiang1.li@intel.com>

docker/Dockerfile.cpu

@@ -118,9 +118,9 @@ ENV CARGO_BUILD_JOBS=4
 # Build the release binary. Cache cargo registry/git and target/, but copy the
 # binary out of the target/ cache mount so it persists into the image layer
 # for later COPY --from=rust-build.
-RUN --mount=type=cache,target=/root/.cargo/registry \
-    --mount=type=cache,target=/root/.cargo/git \
-    --mount=type=cache,target=/workspace/rust/target \
+RUN --mount=type=cache,target=/root/.cargo/registry,sharing=locked \
+    --mount=type=cache,target=/root/.cargo/git,sharing=locked \
+    --mount=type=cache,target=/workspace/rust/target,sharing=locked \
     VLLM_RS_TARGET_PATH=/workspace/vllm-rs bash build_rust.sh
 
 ######################### BUILD IMAGE #########################

vllm/_custom_ops.py

@@ -3537,10 +3537,11 @@ class CPUDNNLGEMMHandler:
         self.handler_tensor: torch.Tensor | None = None
         self.n = -1
         self.k = -1
+        self.dtor = torch.ops._C.release_dnnl_matmul_handler
 
     def __del__(self):
         if self.handler_tensor is not None:
-            torch.ops._C.release_dnnl_matmul_handler(self.handler_tensor.item())
+            self.dtor(self.handler_tensor.item())
 
 
 _supports_onednn = bool(hasattr(torch.ops._C, "create_onednn_mm_handler"))