GitHubCI: fix commitlint workflow

According to conventional-changelog/commitlint#2568 (comment)

Author: knocte

.github/workflows/commitlint.yml

@@ -19,5 +19,5 @@ jobs:
         run: >
           for commit in $(git rev-list ${{ github.base_ref }}..${{
           github.head_ref }}); do
-              npx commitlint --from $commit --to HEAD --verbose
+              npx commitlint --from HEAD~${{ github.event.pull_request.commits }} --to HEAD --verbose
           done