Revert "Enable mina-tree tests"

This reverts commit 2f34ea5.

Author: richardpringle

.github/workflows/tests.yaml

@@ -276,7 +276,7 @@ jobs:
               --exclude mina-macros \
               --exclude mina-p2p-messages \
               --exclude poseidon \
-              --exclude mina-tree \
+              # --exclude mina-tree \
               --exclude snark \
               --exclude p2p \
               --exclude salsa-simple \

ledger/src/lib.rs

@@ -129,8 +129,8 @@ mod wasm {
 #[macro_use]
 mod cache;
 
-// #[cfg(all(not(target_family = "wasm"), feature = "ocaml-interop"))]
-// mod ffi;
+#[cfg(all(not(target_family = "wasm"), feature = "ocaml-interop"))]
+mod ffi;
 
 #[cfg(any(test, feature = "fuzzing"))]
 pub mod generators;