Bump python from 7476637 to 3966b81

Bumps python from `7476637` to `3966b81`.

---
updated-dependencies:
- dependency-name: python
  dependency-type: direct:production
...

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

Dockerfile

@@ -4,7 +4,7 @@
 #
 
 # Using python:3.9-slim
-FROM python@sha256:7476637ee33fae24822294643449e7fe9158708c976ea379037960d3007590a4
+FROM python@sha256:3966b81808d864099f802080d897cef36c01550472ab3955fdd716d1c665acd6
 
 COPY requirements.txt /nca/
 RUN python -m pip install -U pip wheel setuptools && pip install -r /nca/requirements.txt