fix: Fix Dockerfile RUN command continuation (#16)

exporter/Dockerfile

@@ -8,7 +8,7 @@ WORKDIR /app
 # Minimal dependencies for builder stage if any Python packages had C extensions.
 # Assuming requirements.txt does not need gcc or other build tools for now.
 # If pip install fails later, add necessary build tools (e.g., gcc, python3-dev) here.
-RUN apt-get update &&
+RUN apt-get update && \
     # apt-get install -y --no-install-recommends gcc python3-dev # Example if needed
     rm -rf /var/lib/apt/lists/*
 
@@ -23,8 +23,8 @@ WORKDIR /app
 
 # Install iperf3 and its runtime dependency libsctp1 directly in the final stage.
 # This simplifies the Dockerfile by removing the need to copy iperf3 components from the builder.
-RUN apt-get update &&
-    apt-get install -y --no-install-recommends iperf3 libsctp1 &&
+RUN apt-get update && \
+    apt-get install -y --no-install-recommends iperf3 libsctp1 && \
     rm -rf /var/lib/apt/lists/*
 
 # Copy installed Python packages from the builder stage