refactor: use .python-version for docker build

Dockerfile

@@ -1,4 +1,6 @@
-FROM docker.io/library/python:3.12-alpine
+ARG PYTHON_VERSION
+
+FROM docker.io/library/python:${PYTHON_VERSION}-alpine
 
 RUN apk update --no-cache \
     && apk upgrade --no-cache \
@@ -9,14 +11,16 @@ RUN addgroup -g 10001 py \
 
 WORKDIR /var/app
 
-COPY requirements.txt ./
+COPY build/requirements.txt ./
 
 RUN pip install --no-cache-dir --upgrade \
         --requirement requirements.txt
 
 USER 10000:10001
 
-COPY . ./
+COPY run ./
+COPY scripts ./scripts
+COPY unwind ./unwind
 
 ENV UNWIND_DATA="/data"
 VOLUME $UNWIND_DATA