fix: stop preventing any directory or file foo from existing in the…

… project (#334)

This tripped up some test fixtures I wrote where I had inadvertently created
a directory `foo` and hadn't realized they were never actually checked in. Was a bit
of a headscratcher we want to prevent in the future.

.gitignore

@@ -2,4 +2,3 @@
 /iroh_gateway/test_files/*
 .env
 Cargo.lock
-foo