`compression` name collides with standard library in python 3.14

[kyleaoman]

There is a new module in the standard library called compression in python3.14. This collides with the compression package in SOAP, making the SOAP one unimportable. I use the virtual snapshot writer in the testing pipeline for SWIFTGalaxy so this is a little bit problematic. Could compression be moved? Maybe SOAP.compression or SOAP_compression.

[robjmcgibbon]

Could you take a look at the update to make_virtual_snapshot() in #204? I've updated the function so it can now take multiple sets of extra snapshots files. If you think it will still work for you then I will merge it.

[kyleaoman]

That works, yup! I've got an update ready to go (SWIFTSIM/swiftgalaxy#82). Also nice to see the virtual snapshot creation streamlined a bit. Thanks!