doc: fix typo in the release issue template.

Co-Authored-By: Alan Shaw <alan.shaw@protocol.ai>

docs/RELEASE_ISSUE_TEMPLATE.md

@@ -93,7 +93,7 @@ Checklist:
     - [ ] Announce it on the [IPFS Users Mailing List](https://groups.google.com/forum/#!forum/ipfs-users)
 - [ ] **Post-Release**
   - [ ] Bump the version in `version.go` to `vX.(Y+1).0-dev`.
-  - [ ] Create an issue using this release issue template for the _ext_ release.
+  - [ ] Create an issue using this release issue template for the _next_ release.
   - [ ] Make sure any last-minute changelog updates from the blog post make it back into the CHANGELOG.
 
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