Migrate to UBI base images

[dagan]

Instead of using Chainguard, we should use Red Hat's UBI images, which support pinning.

• Go Toolset for UBI 9 as the build image
• UBI 9 Micro for distribution

Tracking issue for:

• [x] https://github.com/raft-tech/konfirm/security/code-scanning/42
• [x] https://github.com/raft-tech/konfirm/security/code-scanning/43
• [x] https://github.com/raft-tech/konfirm/security/code-scanning/44
• [x] https://github.com/raft-tech/konfirm/security/code-scanning/45
• [x] https://github.com/raft-tech/konfirm/security/code-scanning/46
• [x] https://github.com/raft-tech/konfirm/security/code-scanning/47

[dagan]

The Go Toolset ended up not being an option because UBI only supports up to Go 1.21 for some reason. Switched that to the official Go image.