check_spelling_c: update dictionary

check_source/check_spelling_c_config.py

@@ -177,6 +177,7 @@ dict_custom = {
     "overridable",
     "paddings",
     "pannable",
+    "parallelepiped",
     "parallelize",
     "parallelizing",
     "parameterization",
@@ -272,6 +273,7 @@ dict_custom = {
     "subclassing",
     "subdirectories",
     "subdirectory",
+    "suboptimally",
     "subtractive",
     "superset",
     "symmetrize",