check_spelling_c_config: add words

check_source/check_spelling_c_config.py

@@ -52,6 +52,7 @@ dict_custom = {
     "callables",
     "canonicalized",
     "catadioptric",
+    "checksums",
     "confusticate", "confusticated",
     "coplanarity",
     "criterium",
@@ -113,6 +114,7 @@ dict_custom = {
     "renormalize",
     "reparametization",
     "sidedness",
+    "skippable",
     "stitchable",
     "subclass", "subclasses", "subclassing",
     "subdirectory",
@@ -128,7 +130,9 @@ dict_custom = {
     "unparameterized",
     "unregister", "unregisters",
     "unselected",
+    "unsynchronized",
     "untag", "untagging",
+    "untrusted",
     "vectorial",
     "virtualized",
     "volumetrics",