Made builder root again

docker/Dockerfile.builder

@@ -2,7 +2,7 @@
 # Our entire toolchain runs in alpine
 FROM alpine:3.13.5 AS builder
 
-ENV PATH "$PATH:/app/.cargo/bin"
+ENV PATH "$PATH:/root/.cargo/bin"
 # Needed for proper compiling of openssl-dev
 ENV RUSTFLAGS "-C target-feature=-crt-static"
 
@@ -19,13 +19,7 @@ RUN addgroup -S builder && \
         openssl-dev \
         postgresql-dev
 
-# Switch to the non-root user
-USER builder
-
-WORKDIR /app
-
 # Install rustup in the new user's home
 # Create mountpoints for volumes with correct permissions
 RUN { curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh -s -- -y --default-toolchain nightly; } && \
-    rustup target add x86_64-unknown-linux-musl --toolchain nightly && \
-    mkdir -p .cargo/registry target
+    rustup target add x86_64-unknown-linux-musl --toolchain nightly