fix(spells): backfill casting times for all imported spells

data/spells/hide_from_undead.json

@@ -5,6 +5,7 @@
   "range": "touch",
   "save": "will",
   "base_dc": 10,
+  "cast_time": "standard",
   "effects": [],
   "description": "Undead cannot perceive warded creatures (nonintelligent undead ignore them automatically; intelligent undead get a single Will save) until the subject attacks, channels energy, or touches undead. Duration 10 min/level. Saving throw entries here cover the harmless-target save; the undead-perception effect is not modeled by the engine."
 }