Patch ffi payjoin-directory dependency

This patch changes the dependency from using a published version from
crates.io to using a local path dependency. This ensures that we can
still compile the ffi crate with newer versions of the test-utils (which
depends on payjoin-directory) even if the newer versions of the
workspace dependencies are not available on crates.io.

Author: arminsabouri

payjoin-ffi/Cargo.toml

@@ -59,3 +59,4 @@ strip = true
 [patch.crates-io]
 payjoin = { path = "../payjoin" }
 payjoin-test-utils = { path = "../payjoin-test-utils" }
+payjoin-directory = { path = "../payjoin-directory" }