fix: fix pip install problem when docker build

Dockerfile

@@ -9,12 +9,15 @@ COPY . .
 RUN apk add --update --no-cache python3 g++ make py3-pip
 
 # Push client(only support pure text message)
+RUN python3 -m venv /app/venv
+RUN . /app/venv/bin/activate
 RUN pip install apprise
 
 RUN pnpm install --frozen-lockfile
 
 RUN pnpm build
 
+# remove unused source file
 RUN rm -rf ./src
 RUN rm -rf ./website
 RUN rm -rf ./reporter