Fix allcontributors dockerfile

docs/allcontributors.dockerfile

@@ -2,11 +2,10 @@
 # docker build -t allcontributors -f docs/allcontributors.dockerfile .
 # Run with:
 # docker run --rm -v $(pwd):/workspace allcontributors generate
-FROM node:bullseye-slim
+FROM node:20.2.0-bullseye-slim
 
 RUN yarn add --dev all-contributors-cli
 
-ENV HOME=/workspace
 WORKDIR /workspace
 
 ENTRYPOINT ["yarn", "all-contributors"]