chore: remove cache options

Cache was not working correctly, added more complexity and actually made response times slower. Because of this, I'm removing all cache options until we figure out a better solution.

Resolves https://kolaente.dev/vikunja/api/issues/1496
Resolves https://kolaente.dev/vikunja/api/issues/907

pkg/models/models.go

@@ -69,11 +69,6 @@ func SetEngine() (err error) {
 		return
 	}
 
-	// Cache
-	if config.CacheEnabled.GetBool() && config.CacheType.GetString() == "redis" {
-		db.RegisterTableStructsForCache(GetTables())
-	}
-
 	return nil
 }