foundry-list.check Makefile rule erases tests/foundry/out/ag_proofs, which it relies on

[nwatson22]

The Makefile rule tests/foundry/foundry-list.check has tests/foundry/out as an indirect dependency, so when I make it with -B, it erases the tests/foundry/out/ag_proofs directory, and this makes it easy to waste a lot of time by running this rule by mistake because in order to regenerate the foundry-list test file all the proofs in the test-foundry-prove need to be re-run.

Ideally we'd have some way for make to be able to tell if test-foundry-prove needs to be rerun and make this a dependency of tests/foundry/foundry-list.out, but if that's not possible, I think we should move everything currently in tests/foundry/out into its own directory and have tests/foundry/out be only for the generated JSON files.