Tweak tests, consolidate pins target validation (#21254)

buildroot/tests/malyan_M300

@@ -0,0 +1,16 @@
+#!/usr/bin/env bash
+#
+# Build tests for STM32F070CB Malyan M300
+#
+
+# exit on first failure
+set -e
+
+restore_configs
+use_example_configs "delta/Malyan M300"
+opt_disable AUTO_BED_LEVELING_3POINT
+opt_set LCD_SERIAL_PORT 1
+exec_test $1 $2 "Malyan M300 (delta)" "$3"
+
+# cleanup
+restore_configs