Put dependencies in own layer for quicker rebuilds

scripts/Dockerfile

@@ -5,11 +5,12 @@ WORKDIR /ws
 ARG DEBIAN_FRONTEND=noninteractive
 ENV TZ=UTC
 
-COPY . .
-
 RUN ln -snf /usr/share/zoneinfo/$TZ /etc/localtime && \
     echo $TZ > /etc/timezone && \
     apt-get update && \
-    apt-get install -y git g++ cmake ninja-build python3 file && \
-    cmake -G Ninja -S . -B build -DCMAKE_BUILD_TYPE=Release && \
+    apt-get install -y git g++ cmake ninja-build python3 file
+
+COPY . .
+
+RUN cmake -G Ninja -S . -B build -DCMAKE_BUILD_TYPE=Release && \
     cmake --build build