Add missing entry in STAGE0_MISSING_TARGETS

Signed-off-by: Jens Reidel <adrian@travitia.xyz>
diff --git a/src/bootstrap/src/core/sanity.rs b/src/bootstrap/src/core/sanity.rs
index 15e04f5..c839c49 100644
--- a/src/bootstrap/src/core/sanity.rs
+++ b/src/bootstrap/src/core/sanity.rs
@@ -34,6 +34,7 @@ pub struct Finder {
 // Targets can be removed from this list once they are present in the stage0 compiler (usually by updating the beta compiler of the bootstrap).
 const STAGE0_MISSING_TARGETS: &[&str] = &[
     // just a dummy comment so the list doesn't get onelined
+    "aarch64_be-unknown-none-softfloat",
 ];
 
 /// Minimum version threshold for libstdc++ required when using prebuilt LLVM