Bump python from 7476637 to 3966b81 (#731)

Dockerfile

@@ -4,7 +4,7 @@
 #
 
 # Using python:3.9-slim
-FROM python@sha256:7476637ee33fae24822294643449e7fe9158708c976ea379037960d3007590a4
+FROM python@sha256:088d9217202188598aac37f8db0929345e124a82134ac66b8bb50ee9750b045b
 
 COPY requirements.txt /nca/
 RUN python -m pip install -U pip wheel setuptools && pip install -r /nca/requirements.txt