[test-runner] Opt out of shadow call stack

Test: build.py qemu-generic-arm64-test-debug
Bug: 79994372
Change-Id: I43f3c3f62645991f836d83549870f524480f14b2
diff --git a/test-runner/rules.mk b/test-runner/rules.mk
index f06331c..7f9abdf 100644
--- a/test-runner/rules.mk
+++ b/test-runner/rules.mk
@@ -30,6 +30,10 @@
 # not worth the effort
 MODULE_DISABLE_CFI := true
 
+# SCS requires us to allocate a guard region from the heap so it is
+# probably not worth the effort for the same reasons that CFI isn't
+MODULE_DISABLE_SCS := true
+
 QL_TIPC = $(LOCAL_DIR)/../ql-tipc
 
 MODULE_DEFINES += \