docker: remove rust toolchain (#143)

Dockerfile

@@ -2,12 +2,10 @@ FROM ubuntu:23.04
 WORKDIR /bpftime
 RUN apt-get update && apt-get install -y --no-install-recommends \
         libelf1 libelf-dev zlib1g-dev make cmake git libboost1.74-all-dev \
-        binutils-dev libyaml-cpp-dev  gcc g++ ca-certificates clang llvm
-RUN apt-get install -y --no-install-recommends curl && \
-        curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh -s -- -y
+        binutils-dev libyaml-cpp-dev gcc g++ ca-certificates clang llvm
 COPY . .
 RUN git submodule update --init --recursive
 ENV CXX=g++
 ENV CC=gcc
-ENV PATH="${PATH}:/root/.cargo/bin"
-RUN make release -j && make install -j
+RUN make release
+ENV PATH="${PATH}:/root/.bpftime/"