fix(ci): strip trailing slash from RPM_DIR to avoid double slashes

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

script/publish-repo.sh

@@ -1,7 +1,8 @@
 #!/usr/bin/env bash
 set -euo pipefail
 
-RPM_DIR="${1:?usage: $0 <rpm-directory>}"
+RPM_DIR="${1%/}"
+: "${RPM_DIR:?usage: $0 <rpm-directory>}"
 : "${FEDORA_VERSION:?}"
 REMOTE_DIR="/var/www/rpm/fedora/${FEDORA_VERSION}/x86_64"