Github actions diff - Argument list too long

[tropnikovvl]

Hello!

If you make a diff of a large number of changes, you may encounter the error that the arguments list too long.

This is most likely due to the fact that you are putting the output into a variable.
https://github.com/allenporter/flux-local/blob/main/action/diff/action.yml#L116

Is it possible to do optional output to a file? Which I could then read and pass on to another action

[allenporter]

Thank you for the report. Tracking this in #207 so deduping