It is not intended, but RAW creation can make magical items
As DerekStucki's answer shows, Jeremy Crawford's now unofficial ruling here states:
The creation spell is not intended to create magic items.
Using RAW, we do know that spells do what they say and that creation creates a "nonliving object" or "mineral object". It does not specify that they need to be a nonmagical and without that clause nothing prevents you from creating magic items.
A spell which does explicitly forbid magic items is true polymorph; as this Q/A explains there was an errata made to the spell so it now reads:
You transform the creature into a different creature, the creature into a nonmagical object, or the object into a creature
What we know about other methods of crafting magic items is found in the Dungeon Master's Guide which states:
The creation of a magic item is a lengthy, expensive task...
And in the "Crafting Magic Items" section in Xanathar's Guide to Everything which states:
Creating a magic item requires more than just time, effort, and materials. It is a long-term process that involves one or more adventures to track down rare materials and the lore needed to create the item.
Note that these rules are for crafting as a downtime activity. Spells like creation, fabricate, and true polymorph, already bypass/ignore these rules when crafting mundane items (as there is not time requirement like in the dowtime activity rules).
This supports the idea that the creation spell bypasses/ignores these rules even when crafting magic items.
Note that allowing creation to create magical items would be rather out-of-line. This would be allowing a 5th level spell to do something a 9th level spell (true polymorph) cannot even do.
Even the incredibly powerful wish spell has one of the possible uses listed as:
You create one object of up to 25,000 gp in value that isn't a magic item...
As @Rubiksmoose pointed out, magic items created by the creation spell are not permanent and so the comparison to true polymorph and wish is not a complete one. However, I still believe a 5th level spell creating temporary magic items would give the spell an incredible additional amount of utility and still result in an imbalance.
Strictly RAW, because the creation spell does not explicitly forbid the creation of magic items, you can create magic items, but this is not intended and I believe makes the spell overpowered.