fix .dockerignore, build options

Author: gilesknap

.dockerignore

@@ -4,7 +4,5 @@ dist/
 .tox
 .venv*
 venv*
-.devcontainer.json
 .pre-commit-config.yaml
 .vscode
-README.rst

Dockerfile

@@ -22,7 +22,7 @@ WORKDIR /project
 # make the wheel outside of the venv so 'build' does not dirty requirements.txt
 RUN pip install --upgrade pip build && \
     export SOURCE_DATE_EPOCH=$(git log -1 --pretty=%ct) && \
-    python -m build --sdist --wheel && \
+    python -m build && \
     touch requirements.txt
 
 # set up a virtual environment and put it in PATH