fix ansible version pinning in Dockerfile

docker/Dockerfile

@@ -1,7 +1,7 @@
 FROM debian:trixie-slim
 ARG DEBIAN_FRONTEND=noninteractive
 ENV TZ=Europe/Berlin
-ENV ANSIBLE_MAJOR_VERSION=2.20
+ENV ANSIBLE_VERSION=2.20.6
 ENV PIP_BREAK_SYSTEM_PACKAGES=1
 
 RUN apt update && apt install -y --no-install-recommends \
@@ -19,7 +19,7 @@ RUN mkdir -p /etc/ssh/ssh_config.d \
     && printf 'Host *\n  StrictHostKeyChecking no\n  UserKnownHostsFile /dev/null\n' > /etc/ssh/ssh_config.d/99-no-hostkey-check.conf
 
 RUN pip3 install --no-cache-dir --upgrade \
-    ansible-core~=${ANSIBLE_MAJOR_VERSION}
+    ansible-core~=${ANSIBLE_VERSION}
 
 RUN mkdir -p /root/.bashrc.d
 COPY ansible-functs.sh /root/.bashrc.d/ansible-functs.sh