Fix typos with codespell

Using codespell 1.15.0.

Method:
```
$ cat > ../godot-word-whitelist.txt << EOF
ang
curvelinear
doubleclick
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
```

scene/gui/container.cpp

@@ -177,7 +177,7 @@ String Container::get_configuration_warning() const {
 		if (warning != String()) {
 			warning += "\n";
 		}
-		warning += TTR("Container by itself serves no purpose unless a script configures it's children placement behavior.\nIf you dont't intend to add a script, then please use a plain 'Control' node instead.");
+		warning += TTR("Container by itself serves no purpose unless a script configures it's children placement behavior.\nIf you don't intend to add a script, then please use a plain 'Control' node instead.");
 	}
 	return warning;
 }