Pass resolution to tifffile using the current method

[jmuhlich]

We're using a deprecated mechanism to specify the image resolution to tifffile. 2025.2.18 finally removes that mechanism. We need to switch to the new mechanism.

[jmuhlich]

When this is done, we can remove the <2025.2.18 pin from the install instructions.

[josenimo]

Dear @jmuhlich,

for some reason your commit about the resolution parameter did not get included in the release. I am installing v1.19.0, and reg.py at 1289, still looks like this:

resolution=(resolution_cm, resolution_cm, "centimeter"),
# FIXME Propagate this from input files (especially RGB).

The last commit in the current release is from Nov 25, 2024.
The fixing commit is from Aug 11, 2025.
I suggest creating a new release :)