[Feature Request] Make Docker Python version configurable

[adam-lagoda]

Is your feature request related to a problem? Please describe.
When building a Docker image for the flow using
pf flow build --source ./flows/standard --output dist --format docker
the resulting Dockerfile contains
RUN conda create -n promptflow-serve python=3.9.16 [..]
by default.

It would be great if the python version of the deployment would be configurable.
The template for the Dockerfile can be found here
src/promptflow-devkit/promptflow/_sdk/data/docker/Dockerfile.jinja2

Describe the solution you'd like
I would like the python version to be configurable by a flag. If a flag is missing, then the version and fall to a default 3.9.16 as is now,

Describe alternatives you've considered
The python version for the Dockerfile conda environment could be parsable from the active environment that is used for the build.
If, if I run
pf flow build [...]
from my conda env with python 3.12.4, I would like to see
RUN conda create -n promptflow-serve python=3.12.4 [..]
in the Dockerfile

Additional context
Add any other context or screenshots about the feature request here.