fix(ci): reset checkout before canary publish

changesets/action modifies the working directory when creating the
version PR (bumps version, deletes changeset files). The canary step
was running in that modified state, publishing the bumped version
with the canary tag instead of a proper snapshot.

Fix: checkout the original commit before running canary snapshot.

Author: piotrski

.github/workflows/release.yml

@@ -53,5 +53,8 @@ jobs:
       - name: Publish canary snapshot
         if: steps.changesets.outputs.published != 'true'
         run: |
+          git checkout ${{ github.sha }}
+          bun install
+          bun run build
           npx changeset version --snapshot canary
           npx changeset publish --tag canary --no-git-tag