Puts create_tmp_accounts_dir_for_tests() behind DCOU

runtime/src/snapshot_utils.rs

@@ -2170,6 +2170,11 @@ pub fn should_take_incremental_snapshot(
         && last_full_snapshot_slot.is_some()
 }
 
+/// Creates an "accounts path" directory for tests
+///
+/// This temporary directory will contain the "run" and "snapshot"
+/// sub-directories required by a validator.
+#[cfg(feature = "dev-context-only-utils")]
 pub fn create_tmp_accounts_dir_for_tests() -> (TempDir, PathBuf) {
     let tmp_dir = tempfile::TempDir::new().unwrap();
     let account_dir = create_accounts_run_and_snapshot_dirs(&tmp_dir).unwrap().0;