utils/dicom_converter: bump NumPy version

The current one has an (admittedly disputed) vulnerability (CVE-2021-41495).
Note that 2.2.6 is the most recent release that still supports our lowest
supported Python version (3.10).

Author: SpecLad

utils/dicom_converter/requirements.txt

@@ -1,4 +1,4 @@
-numpy==1.22.0
+numpy==2.2.6
 Pillow==12.1.1
 pydicom==2.4.5
 tqdm==4.66.3