update pydicom

I updated pydicom to the latest version due to CVE-2026-32711.

Unfortunately, the upstream developer made quite a few changes, requiring a=
 lot of adjustments.
I uploaded everything to Salsa:
https://salsa.debian.org/med-team/pydicom/-/tree/master
Locally, it only builds with a few warnings, but the job has problems in th=
e Salsa CI:
https://salsa.debian.org/med-team/pydicom/-/jobs/9554086
Unfortunately, I can't figure out why.

Who has time to look at the changes?
If it's okay, please finalize the release and upload it, or give me DM uplo=
ad rights so I can finalize it myself.

Thanks and best regards,
Karsten

PS: I'm also preparing a PU for stable to fix the CVE.