check_spelling: ignore common suffix's when hyphenated

Allow informal convention of adding -ish or -ness onto the end of any word.
This is done a handful of times and seems reasonable to support.

check_source/check_spelling.py

@@ -74,6 +74,7 @@ from check_spelling_c_config import (
     dict_custom,
     dict_ignore,
     dict_ignore_hyphenated_prefix,
+    dict_ignore_hyphenated_suffix,
     files_ignore,
 )
 
@@ -114,8 +115,13 @@ def dictionary_check(w: str) -> bool:
 
             # Allow: `un-word`, `re-word`.
             w_split = w.strip("-").split("-")
+            if len(w_split) > 1:
                 if w_split and w_split[0].lower() in dict_ignore_hyphenated_prefix:
                     del w_split[0]
+            # Allow: `word-ish`, `word-ness`.
+            if len(w_split) > 1:
+                if w_split and w_split[-1].lower() in dict_ignore_hyphenated_suffix:
+                    del w_split[-1]
 
             for w_sub in w_split:
                 if w_sub:

check_source/check_spelling_c_config.py

@@ -450,6 +450,11 @@ dict_ignore_hyphenated_prefix = {
     "un",
 }
 
+dict_ignore_hyphenated_suffix = {
+    "ish",
+    "ness",
+}
+
 files_ignore = {
     "source/tools/utils_doc/rna_manual_reference_updater.py",  # Contains language ID references.
 }