Drop Rates of Karazhan enchants should be greatly reduced during TBC

https://github.com/chromiecraft/chromiecraft/issues/4867
### Current Behaviour

Enchants have a 100% drop rate inside Karazhan

### Expected Blizzlike Behaviour

It has a 4-5% drop chance for the weapon enchants
6% for surefooted

### Source

Wowhead
https://www.wowhead.com/tbc/item=22559/formula-enchant-weapon-mongoose
https://www.wowhead.com/tbc/item=22561/formula-enchant-weapon-soulfrost
https://www.wowhead.com/tbc/item=22560/formula-enchant-weapon-sunfire
https://www.wowhead.com/tbc/item=22545/formula-enchant-boots-surefooted

It has a 4-5% for the weapon enchants
6% for surefooted

Potentially only revert with Ulduar
https://wowpedia.fandom.com/wiki/Patch_3.1.0#Enchanting

Start by reviewing the linked issue #4867 and the Wowhead references for the stated drop rates. No files, tests, or code entry points are named; done means Karazhan enchant drops match the intended TBC rates, with the Ulduar-era change considered.

Written by the indexing model from the issue text.