[infra] Upgrade changesets and remove Prettier version override (#3255)

Previously, weirdness would occur on release because of differences in the Prettier formatting for our CHANGELOG files between our auto-formatter and the formatting that Changesets itself tries to do. This was because Changesets had an old version of Prettier, but our repo had a newer version.

We had a workaround for this where we deleted Changesets' version of Prettier, so that ours would be prefered.

Now that changesets/changesets#905 has landed (fixing changesets/changesets#616), Changesets will prefer our version of Prettier. Plus the version they depend on is now up to date. So we can remove the workaround.

.changeset/eight-frogs-roll.md

@@ -0,0 +1,2 @@
+---
+---

.github/workflows/release.yaml

@@ -36,13 +36,6 @@ jobs:
         working-directory: lit
         run: npm ci
 
-      # Changeset uses prettier@1 which creates unstable formatting issues
-      # Deleting this forces fallback to our version of prettier
-      # https://github.com/changesets/changesets/issues/616
-      - name: Remove old version of prettier from changesets
-        working-directory: lit
-        run: rm -rf node_modules/@changesets/*/node_modules/prettier
-
       - name: Create Release Pull Request or Publish to npm
         # The id of this step must not be "changesets", or else the step will be invisible
         # in the list of steps from the GitHub UI when the action runs (though it will still