py/mpconfig: Include micropython module in core features.

This excludes it from the minimal builds.

Signed-off-by: Laurens Valk <laurens@pybricks.com>

py/mpconfig.h

@@ -1313,7 +1313,7 @@ typedef double mp_float_t;
 
 // Whether to provide "micropython" module
 #ifndef MICROPY_PY_MICROPYTHON
-#define MICROPY_PY_MICROPYTHON (1)
+#define MICROPY_PY_MICROPYTHON (MICROPY_CONFIG_ROM_LEVEL_AT_LEAST_CORE_FEATURES)
 #endif
 
 // Whether to provide "gc" module

tests/basics/nanbox_smallint.py

@@ -1,6 +1,10 @@
 # Test creating small integers without heap allocation in nan-boxing mode.
 
-import micropython
+try:
+    import micropython
+except ImportError:
+    print("SKIP")
+    raise SystemExit
 
 try:
     # Test for nan-box build by allocating a float while heap is locked.