Fix version name in update tag workflow (#23)

Author: blink1073

.github/workflows/update-action-tag.yml

@@ -40,7 +40,7 @@ jobs:
  - name: Create a new signed tag
  uses: ./git-sign
  with:
- command: git tag -a \"${{ env.VERSION }}\" -m \"Update tag\" -s --local-user=${{ env.GPG_KEY_ID }}
+ command: git tag -a \"v${{ env.VERSION }}\" -m \"Update tag\" -s --local-user=${{ env.GPG_KEY_ID }}
 
  - name: Push the tag
  run: