Remove duplicate Kickstarter tutorial (upstream Hiro content bug)

The Hiro source file build-a-decentralized-kickstarter.mdx has the
title "Build a decentralized Kickstarter" but its body is identical
to the NFT marketplace guide. Rather than ship duplicate content,
removing it until the upstream source is corrected.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: huth-stacks

docs/tutorials/SUMMARY.md

@@ -37,5 +37,4 @@
 ## Hiro Guides
 
 * [Build an NFT Marketplace](build-an-nft-marketplace.md)
-* [Build a Decentralized Kickstarter](build-a-decentralized-kickstarter.md)
 * [Build a No-Loss Lottery Pool](no-loss-lottery.md)