refactor(ci/docker/dist-x86_64-linux): remove rustc-perf downloading

It is now available as a submodule in src/tools/rustc-perf, and is
initialized when building opt-dist

Author: lovesegfault

src/ci/docker/host-x86_64/dist-x86_64-linux/Dockerfile

@@ -58,14 +58,6 @@ COPY host-x86_64/dist-x86_64-linux/build-clang.sh /tmp/
 RUN ./build-clang.sh
 ENV CC=clang CXX=clang++
 
-# rustc-perf version from 2023-10-22
-# Should also be changed in the opt-dist tool for other environments.
-ENV PERF_COMMIT 4f313add609f43e928e98132358e8426ed3969ae
-RUN curl -LS -o perf.zip https://ci-mirrors.rust-lang.org/rustc/rustc-perf-$PERF_COMMIT.zip && \
-    unzip perf.zip && \
-    mv rustc-perf-$PERF_COMMIT rustc-perf && \
-    rm perf.zip
-
 COPY scripts/sccache.sh /scripts/
 RUN sh /scripts/sccache.sh