Filenames with colons are problematic for at least some software

I generated response files using test_script_combine.py and it worked great. So I went to view the responses. The response evaluation tool I use (JPlotResp - it's old) isn't able to parse a file with this name:

irisws-nrl-2024-08-13T13:10:03.336970.resp

but it is able to parse the same file with this filename:

irisws-nrl-2024-08-13T13_10_03.336970.resp

Substituting underscores for colons in the time part would also make file naming match that of the web service.