Add rpms-signature-scan to the konflux builds #2085

Namespace: <a href="https://detailurl.setting.custom-console-url-namespace.is.not.configured" rel="nofollow">acscs-rhacs-tenant
PipelineRun: <a href="https://console.redhat.com/application-pipeline/ns/acscs-rhacs-tenant/pipelinerun/acs-fleetshard-operator-on-pull-request-sjdsb" rel="nofollow">acs-fleetshard-operator-on-pull-request-sjdsb

Success

Red Hat Konflux/acs-fleetshard-operator-on-pull-request has successfully validated your commit.

Status	Duration	Name
✅ Succeeded	5 seconds	init
✅ Succeeded	17 seconds	clone-repository
✅ Succeeded	1 minute	build-container
✅ Succeeded	10 seconds	build-image-index
✅ Succeeded	1 minute	clamav-scan
✅ Succeeded	17 seconds	rpms-signature-scan
✅ Succeeded	1 minute	clair-scan
✅ Succeeded	12 seconds	deprecated-base-image-check
✅ Succeeded	36 seconds	ecosystem-cert-preflight-checks
✅ Succeeded	47 seconds	push-dockerfile
✅ Succeeded	19 seconds	sast-snyk-check
✅ Succeeded	8 seconds	apply-tags
✅ Succeeded	10 seconds	show-summary
✅ Succeeded	7 seconds	show-sbom