Provide option to pause Modrinth and CF projects upgrade

[itzg]

It has been mentioned that it would be helpful to pause the auto upgrade behavior of MODRINTH_PROJECTS and CURSEFORGE_FILES. Pinning the versions of every project/file is not practical in some cases.

Discord discussion

[aidanfoss]

Is this just going to be a boolean env var (UPDATE_MODS: TRUE/FALSE) or are you thinking something that could potentially be more useful? Something like a timed update (every 3 months) could be done instead, although that would still lead to the occasional breaks.

can you not just do something like this?
Add the list of mods at the top of the stack and just comment out the modrinth_projects env to prevent it from downloading?

ex.yml

[itzg]

      #MODRINTH_PROJECTS: *mods comment this to stop updates?

accidentally works right now. Really an empty MODRINTH_PROJECTS should be handled as a removal of all the previously managed mods since the feature also removes files as they're removed from the list.

I can however have the script differentiate between an unset variable and an empty variable. That's probably what should be included in this feature.