chore: remove stale boxo-migrate references from README (#1119)

The `cmd/boxo-migrate` tool was removed in #1113.

Author: lidel

README.md

@@ -30,7 +30,6 @@
   - [Is everything related to IPFS in the Go ecosystem in this repo?](#is-everything-related-to-ipfs-in-the-go-ecosystem-in-this-repo)
 - [Consuming](#consuming)
   - [Getting started](#getting-started)
-  - [Migrating to Boxo](#migrating-to-boxo)
   - [Deprecations and Breaking Changes](#deprecations-and-breaking-changes)
 - [Development](#development)
   - [Should I add my IPFS component to Boxo?](#should-i-add-my-ipfs-component-to-boxo)
@@ -101,25 +100,6 @@ No. Not everything related to IPFS is intended to be in Boxo. View it as a start
 
 See [examples](./examples/README.md).
 
-If you are migrating to Boxo, see [Migrating to Boxo](#migrating-to-boxo).
-
-### Migrating to Boxo
-
-Many Go modules under github.com/ipfs have moved here. Boxo provides a tool to ease this migration, which does most of the work for you:
-
-* `cd` into the root directory of your module (where the `go.mod` file is)
-* Run: `go run github.com/ipfs/boxo/cmd/boxo-migrate@latest update-imports`
-  * This will upgrade your module to Boxo v0.8.0 and rewrite your import paths
-* Run: `go run github.com/ipfs/boxo/cmd/boxo-migrate@latest check-dependencies`
-  * This will print unmaintained dependencies you still have
-  * These aren't necessarily an immediate problem, but you should eventually get them out of your dependency graph
-  
-This tool only upgrades your module to Boxo v0.8.0, to minimize backwards-incompatible changes. Depending on the versions of IPFS modules before the upgrade, your code may require additional changes to build.
-
-We recommend upgrading to v0.8.0 first, and _then_ upgrading to the latest Boxo release.
-
-If you encounter any challenges, please [open an issue](https://github.com/ipfs/boxo/issues/new/choose) and Boxo maintainers will help you.
-
 ### Deprecations and Breaking Changes
 
 See [RELEASE.md](./RELEASE.md).