Merge pull request 'Make python package install cacheable' (#2) from perillamint/minya_hotomoe:dev/docker-ci into main

Reviewed-on: #2

Dockerfile

@@ -5,8 +5,10 @@ RUN apt-get update && apt-get install -y libgl1 && rm -rf /var/lib/apt/lists/*
 RUN mkdir -p /opt/minya
 WORKDIR /opt/minya
 
-ADD . /opt/minya
+ADD requirements.txt /opt/minya
 
 RUN python3 -m pip install -r requirements.txt
 
+ADD . /opt/minya
+
 CMD ["python3", "minya.py"]