Exception when invoking configure.py multiple time

python3 configure.py build --password 1234
0|agx@quark:/var/scratch/librem5/phosh-recipes (doc-updates)$ python3 configure.py build --password 1234 
Traceback (most recent call last):
  File "/var/scratch/librem5/phosh-recipes/configure.py", line 120, in <module>
    main()
    ~~~~^^
  File "/var/scratch/librem5/phosh-recipes/configure.py", line 80, in main
    args.build_directory.mkdir()
    ~~~~~~~~~~~~~~~~~~~~~~~~~~^^
  File "/usr/lib/python3.13/pathlib/_local.py", line 724, in mkdir
    os.mkdir(self, mode)
    ~~~~~~~~^^^^^^^^^^^^
FileExistsError: [Errno 17] File exists: 'build'

(we don't need to overdo error handling but lets catch the common ones)