Bump python in /{{ cookiecutter.project_name }}/docker/dist/celery

Bumps python from 3.9.1-alpine3.13 to 3.9.7-alpine3.13.

---
updated-dependencies:
- dependency-name: python
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <support@github.com>

{{ cookiecutter.project_name }}/docker/dist/celery/Dockerfile

@@ -1,6 +1,6 @@
 FROM {{ cookiecutter.project_name }}_dev_app:latest as builder
 
-FROM python:3.9.1-alpine3.13
+FROM python:3.9.7-alpine3.13
 
 COPY --from=builder /root/.cache /root/.cache
 COPY --from=builder /app /app