Update python Docker tag to v3.12

Dockerfile

@@ -1,4 +1,4 @@
-FROM python:3.10
+FROM python:3.12
 RUN pip install --no-cache-dir scanpy spatialtis==0.5.0rc0 lightgbm scikit-image leidenalg \
     jupyter jupyterlab jupyter_http_over_ws ipywidgets
 WORKDIR /analysis

benchmark/time-squidpy.Dockerfile

@@ -1,3 +1,3 @@
-FROM python:3.9
+FROM python:3.12
 WORKDIR /usr/src/app
 RUN pip install --no-cache-dir squidpy memory_profiler