Fix typos with codespell

Using codespell 1.17.1.

Method:
```
$ cat > ../godot-word-whitelist.txt << EOF
ang
curvelinear
dof
doubleclick
fave
findn
leapyear
lod
merchantibility
nd
numer
ois
ony
que
seeked
synching
te
uint
unselect
webp
EOF

$ codespell -w -q 3 -I ../godot-word-whitelist.txt --skip="./thirdparty,*.po"
$ git diff // undo unwanted changes
```

modules/gdscript/gdscript_tokenizer.cpp

@@ -578,7 +578,7 @@ GDScriptTokenizer::Token GDScriptTokenizer::potential_identifier() {
 }
 
 void GDScriptTokenizer::newline(bool p_make_token) {
-	// Don't overwrite previous newline, nor create if we want a line contination.
+	// Don't overwrite previous newline, nor create if we want a line continuation.
 	if (p_make_token && !pending_newline && !line_continuation) {
 		Token newline(Token::NEWLINE);
 		newline.start_line = line;