Cached recipe tracking issue

just now has a [cache] attribute added in #3437 and released in 1.54.0 which skip recipe invocations if an entry matching the invocation is found in an on-disk cache.

This is a complex feature, so try it out and let me know what you think!

Possible future additions:

• Check input file mtime instead of hashing
• Invalidate cache if an executable changes
• Remove automatically added cache keys
• Allow input files to be directories
• Cache shell recipes
• Allow referencing extra, inputs, and outputs in recipe