ci: rely on bump to refuse an existing tag

.github/workflows/release.yml

@@ -56,37 +56,13 @@ jobs:
         with:
           bump: calver
           version-source: tag
+          token: ${{ steps.setup-git-user.outputs.token }}
           targets: |
             - file: CITATION.cff
               pattern: '^version: {version}$'
             - file: CITATION.cff
               pattern: '^date-released: "{date}"$'
 
-      # The release step refuses an existing tag or release too, but only after
-      # the push, which would leave the bump on the default branch.
-      - name: Refuse an existing tag or release
-        env:
-          GH_TOKEN: ${{ steps.setup-git-user.outputs.token }}
-          VERSION: ${{ steps.bump.outputs.version }}
-        shell: bash
-        run: |
-          set -euo pipefail
-          STATUS=0
-          git ls-remote --exit-code --tags origin "refs/tags/${VERSION}" > /dev/null || STATUS=$?
-          case "${STATUS}" in
-            0) echo "::error::Tag ${VERSION} already exists. Delete it, or create its release by hand, then dispatch this workflow again."; exit 1 ;;
-            2) ;;
-            *) echo "::error::Could not list the tags of origin (git exit ${STATUS})."; exit 1 ;;
-          esac
-          if OUTPUT=$(gh release view "${VERSION}" 2>&1); then
-            echo "::error::A release ${VERSION} already exists, perhaps as a draft. Delete it, then dispatch this workflow again."
-            exit 1
-          fi
-          if ! grep -qi 'release not found' <<< "${OUTPUT}"; then
-            echo "::error::Could not check for release ${VERSION}: ${OUTPUT}"
-            exit 1
-          fi
-
       # The App is exempt from the pull request rule of the default branch, and
       # [skip ci] keeps CI from running again on a tree it has checked.
       - name: Push the version