build: Bump python from 3.9.2-slim-buster to 3.9.4-slim-buster (#11)

Bumps python from 3.9.2-slim-buster to 3.9.4-slim-buster.

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

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

Dockerfile

@@ -1,5 +1,5 @@
 # TODO: Find out whether it possible to use "faster" base Python image
-FROM python:3.9.2-slim-buster as python-base
+FROM python:3.9.4-slim-buster as python-base
 
 LABEL maintainer="Igor Davydenko <iam@igordavydenko.com>"
 LABEL description="Add poetry, pre-commit, and other dev-tools to official Python slim Docker image."