TST: Bump stable job to Python 3.13

[pllim]

Description

Bump stable job to Python 3.13 because some packages new releases dropped support for Python 3.10

[pllim]

M. Marinelli triggered this warning possibly using scikit-image 0.26.0 (released 2025-12-20):

res, err = detsat(fits_files[1], chips=[1, 4], plot=True, verbose=True, percentile=(50, 95))

FutureWarning: Parameter min_size is deprecated since version 0.26.0 and will be removed in 2.0.0

acstools/acstools/satdet.py

Lines 216 to 218 in 85450f1

	# clean up the small objects, will make less noise
	morph.remove_small_objects(edge, min_size=small_edge, connectivity=8,
	out=edge)

• stable job was using too old of a Python, which I am bumping in this PR to pick up scikit-image 0.26.0 for that job
• dev job did pick up scikit-image 0.26.0 on master branch already because it is not finding a dev version (problem for TST: Force scikit-image dev in devdeps #245 to solve another day)

However, the tests here (https://github.com/spacetelescope/acstools/blob/master/acstools/tests/test_wfc_satdet.py) are not triggering the warning that user found.

Also see:

• Use max_size in remove_small_(holes|objects) scikit-image/scikit-image#7739