Cleanup: spelling (make check_spelling_*)

Also exclude some files that have too many false positives.

tools/check_source/check_spelling_config.py

@@ -905,6 +905,8 @@ dict_ignore_hyphenated_suffix = {
 }
 
 files_ignore = {
+    "scripts/modules/bl_i18n_utils/utils_spell_check.py",  # UI spelling, doesn't always match code spelling.
+    "tools/utils/git_data_canonical_authors.py",  # Too many names which aren't in the dictionary.
     "tools/utils_doc/rna_manual_reference_updater.py",  # Contains language ID references.
 
     # Maintained by 3rd parties.