add dependabot, trivy, update deps, and fix vulns in deps

[vroldanbet]

• adds dependabot so we get dependencies updated regularly
• adds trivy as vulnerability scanning tool in CI
• addresses all reported vulnerabilities by updating dependencies
• updates all dependencies to latest version
• regenerated protos to 1.28.1
• add CODEOWNERS
• updates GitHub Actions jobs to be aligned with authzed/spicedb: yamlint, codeql, CLA update

note: there are some diffs created by the proto generator locally that do not show up in CI and cause a diff. I had to manually remove those changes (they where a space in a comment)