ci: Only auto update v3

We had a breaking change and I should have stopped updating v2 as a
moving tag.

This was highlighted by @mmontesi in #76 (comment)

.github/workflows/ci.yml

@@ -48,8 +48,8 @@ jobs:
         env:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
         run: |
-          git tag -d v2
-          git push --delete origin v2
-          git push origin :refs/tags/v2
-          git tag v2
+          git tag -d v3
+          git push --delete origin v3
+          git push origin :refs/tags/v3
+          git tag v3
           git push --tags