* layers/+lang/python/packages.el: Fix importmagic leak

[sunlin7]

Hi,

There is a serious resource leak when enable python layer with importmage package enabled.
The reproduce steps are:

1. enable python layer, and the imortmagic should also be instralled for its python layer dependency.
2. open a python source code,
3. start python interpreter
4. execute python-shell-send-buffer or other send function.
5. execute list-processes to show the process
   You will see every time execute the step 4, the epc:server in process list will increaced.
   The reason is the emacs-29 had enhanced implementation for with-temp-buffer which won't call the kill-buffer-hook while the importmagic-mode will create epc:server on mode hook and stop the epc:server on kill-buffer-hook but it won't be called for temp buffer.
   This change will fix the issue with avoiding starting the epc:server for temp buffer.

Please help review and merge the patch. Thanks

[smile13241324]

Thanks for fixing this :)

[sunlin7]

@smile13241324 Thank goodness you're back!

[smile13241324]

No worries ;), I just need some breaks from time to time you know surgeries and stuff.