Update python Docker tag to v3.9.21

.drone.yml

@@ -15,7 +15,7 @@ trigger:
 
 steps:
   - name: install-lint-test
-    image: python:3.9.20-alpine@sha256:693ebbf7675c189850df99918ed3002ead3ac99753bc56b16fd7ee636251a958
+    image: python:3.9.21-alpine@sha256:e377d393562f2ba8875d3527c9171fd5f634ebacdf92e121701ecd08d7da4f66
     env:
       PYROOT: '/pyroot'
       PYTHONUSERBASE: '/pyroot'
@@ -104,7 +104,7 @@ trigger:
 
 steps:
   - name: install-lint-test
-    image: python:3.9.20-alpine@sha256:693ebbf7675c189850df99918ed3002ead3ac99753bc56b16fd7ee636251a958
+    image: python:3.9.21-alpine@sha256:e377d393562f2ba8875d3527c9171fd5f634ebacdf92e121701ecd08d7da4f66
     env:
       PYROOT: '/pyroot'
       PYTHONUSERBASE: '/pyroot'

.python-version

@@ -1 +1 @@
-3.9.20
+3.9.21

Dockerfile

@@ -2,7 +2,7 @@
 #
 # SPDX-License-Identifier: AGPL-3.0-or-later
 
-FROM python:3.9.20-alpine@sha256:693ebbf7675c189850df99918ed3002ead3ac99753bc56b16fd7ee636251a958 AS builder
+FROM python:3.9.21-alpine@sha256:e377d393562f2ba8875d3527c9171fd5f634ebacdf92e121701ecd08d7da4f66 AS builder
 
 ENV PYROOT=/pyroot
 ENV PYTHONUSERBASE=$PYROOT
@@ -20,7 +20,7 @@ RUN PIP_USER=1 PIP_IGNORE_INSTALLED=1 pipenv install --system --deploy --ignore-
 RUN pip3 uninstall --yes pipenv
 
 
-FROM python:3.9.20-alpine@sha256:693ebbf7675c189850df99918ed3002ead3ac99753bc56b16fd7ee636251a958 AS ki-backend
+FROM python:3.9.21-alpine@sha256:e377d393562f2ba8875d3527c9171fd5f634ebacdf92e121701ecd08d7da4f66 AS ki-backend
 
 ENV PYROOT=/pyroot
 ENV PYTHONUSERBASE=$PYROOT