docker: clean apt cache and add --no-install-recommends in Dockerfile.ubuntu

Author: Algorithm5838

Dockerfile.ubuntu

@@ -26,7 +26,8 @@ RUN echo "finished building redlib!"
 FROM ubuntu:${UBUNTU_RELEASE_VERSION} AS release
 
 # Install ca-certificates
-RUN apt-get update && apt-get install -y ca-certificates
+RUN apt-get update && apt-get install -y --no-install-recommends ca-certificates \
+    && rm -rf /var/lib/apt/lists/*
 
 # Import redlib binary from builder
 COPY --from=builder /redlib/target/release/redlib /usr/local/bin/redlib