Fix to drop obsolete secret

Author: iliaross

.github/workflows/virtualmin.dev+virtualmin-registrar.yml

@@ -24,4 +24,3 @@ jobs:
       DEV_UPLOAD_SSH_DIR: ${{ secrets.DEV_UPLOAD_SSH_DIR }}
       PRERELEASE_UPLOAD_SSH_DIR: ${{ secrets.PRERELEASE_UPLOAD_SSH_DIR }}
       DEV_SSH_PRV_KEY: ${{ secrets.DEV_SSH_PRV_KEY }}
-      DEV_SIGN_BUILD_REPOS_CMD: ${{ secrets.DEV_SIGN_BUILD_REPOS_CMD }}