skip stage 0 target check if BOOTSTRAP_SKIP_TARGET_SANITY is set

Signed-off-by: onur-ozkan <work@onurozkan.dev>

Author: onur-ozkan

src/bootstrap/src/core/sanity.rs

@@ -234,8 +234,7 @@ than building it.
         }
 
         // Ignore fake targets that are only used for unit tests in bootstrap.
-        #[cfg(not(feature = "bootstrap-self-test"))]
-        {
+        if cfg!(feature = "bootstrap-self-test") && !skip_target_sanity {
             let mut has_target = false;
             let target_str = target.to_string();