fix(compilation): use cross for statically linking against musl

Dockerfile

@@ -1,19 +1,4 @@
-FROM rust:1.54
+FROM scratch
 
-ENV PREFIX="/usr/src/out/prefix" \
-    CC="musl-gcc -fPIC -pie -static" \
-    LD_LIBRARY_PATH="$PREFIX" \
-    PKG_CONFIG_PATH="/usr/local/lib/pkgconfig" \
-    PATH="/usr/local/bin:/root/.cargo/bin:$PATH"
-
-RUN apt update && \
-    apt install -y --no-install-recommends \
-        musl-dev \
-        musl-tools \
-        libpq-dev \
-        libssl-dev && \
-    rustup target add x86_64-unknown-linux-musl && \
-    mkdir "$PREFIX" && \
-    echo "$PREFIX/lib" >> /etc/ld-musl-x86_64.path
-
-WORKDIR /usr/src/app
+COPY target/x86_64-unknown-linux-musl/release/rbd /
+RUN ["/rbd"]