FIX: Warlock spells search
The default behavior of the spell filter by class was to hide all spells from levels for which the selected class has no spell slots. This works well for Fighters (Eldritch Knight) and Rogue (Arcane Trickster) for example, as they use spells from the Wizard list, but only have access to spells up to level 4.
The Warlock, on the other hand, is a strange class, the only one in fact that has spells on its list for which it has no spell slots. The only way to cast these spells of levels higher than 5 is with the "Mystic Arcanum" class feat.
The fact that the Warlocks do not have spell slots of levels 6 to 9 meant that spells of these levels did not appear in the list when the class was selected in the filters.