Fix RPM GnuPG dependency on SUSE

[ilysenko]

Summary

• select gpg2 for updater-enabled RPM builds on openSUSE/SLES
• retain gnupg2 for Fedora and other RPM environments
• add regression coverage for both distro branches and updater-disabled packages

Fixes #1362

Tests

• node --test scripts/lib/package-common.test.js
• bash tests/scripts_smoke.sh
• bash -n scripts/build-rpm.sh scripts/install-deps.sh
• rpmspec -q --requires with and without suse_version
• CI_SKIP_PULL=1 ./scripts/ci-local.sh rpm
• git diff --check

Notes

The dependency choice is evaluated at RPM build time, matching the native make bootstrap-native workflow reported in the issue.