docs: remove nft.storage references

nft.storage transitioned to read-only mode in 2025.

https://nft.storage/blog/nft-storage-operation-transitions-in-2025

Author: lidel

docs/concepts/persistence.md

@@ -48,7 +48,6 @@ Some of the pinning services listed below are operated by third party companies.
 
 - [4EVERLAND Bucket](https://www.4everland.org/bucket/)
 - [Filebase](https://filebase.com/)
-- [NFT.Storage](https://nft.storage/)
 - [Pinata](https://pinata.cloud/)
 - [Storacha (formerly web3.storage)](https://storacha.network/)
 

docs/how-to/best-practices-for-nft-data.md

@@ -139,9 +139,7 @@ When your data is stored on IPFS, users can fetch it from any IPFS node that has
 
 If you're building a platform using IPFS for storage, it's important to pin your data to IPFS nodes that are robust and highly available, meaning that they can operate without significant downtime and with good performance. See our [server infrastructure documentation][docs-server-infra] to learn how [IPFS Cluster][ipfs-cluster] can help you manage your own cloud of IPFS nodes that coordinate to pin your platform's data and provide it to your users.
 
-Alternatively, you can delegate the infrastructure responsibility to a remote pinning service. Remote pinning services like [Pinata](https://pinata.cloud), [Storacha](https://storacha.network/), and [Filebase](https://filebase.com/) provide redundant, highly-available storage for your IPFS data, without any _vendor lock-in_. Because IPFS-based content is addressed by CID instead of location, you can switch between pinning services or migrate to your private infrastructure seamlessly as your platform grows. 
-
-You can also use a service from [Protocol Labs](https://protocol.ai) called [nft.storage](https://nft.storage) to get your data into IPFS, with long-term persistence backed by the decentralized [Filecoin](https://filecoin.io) storage network. To help foster the growth of the NFT ecosystem and preserve the new _digital commons_ of cultural artifacts that NFTs represent, [nft.storage](https://nft.storage) provides free storage and bandwidth for public NFT data. Sign up for a free account at [https://nft.storage](https://nft.storage) and try it out!
+Alternatively, you can delegate the infrastructure responsibility to a remote pinning service. Remote pinning services like [Pinata](https://pinata.cloud), [Storacha](https://storacha.network/), and [Filebase](https://filebase.com/) provide redundant, highly-available storage for your IPFS data, without any _vendor lock-in_. Because IPFS-based content is addressed by CID instead of location, you can switch between pinning services or migrate to your private infrastructure seamlessly as your platform grows.
 
 To learn more about persistence and pinning, including how to work with remote pinning services, see our [overview of persistence, permanence, and pinning][docs-persistence].