add a 'zot scrub' cmd to check integrity

What's Changed

• ci/cd: fix arch builds to pick correct file by @rchincha in #328
• Implement "scrub" to check manifest/blob integrity by @Andreea-Lupu in #236

New Contributors

• @Andreea-Lupu made their first contribution in #236

Full Changelog: v1.3.5...v1.3.6