chore(deps): update python docker tag to v3.14

Author: renovate[bot]

Dockerfile

@@ -1,14 +1,14 @@
 ARG INSTALL_EXTRAS=irc,XMPP,telegram,slack
 
-FROM python:3.9 AS build
+FROM python:3.14 AS build
 ARG INSTALL_EXTRAS
 
 WORKDIR /wheel
 
 COPY . .
 RUN pip wheel --wheel-dir=/wheel wheel . .[${INSTALL_EXTRAS}]
 
-FROM python:3.9-slim
+FROM python:3.14-slim
 ARG INSTALL_EXTRAS
 
 RUN --mount=from=build,source=/wheel,target=/wheel \