Update Gitlab Shell version to 14.23.0

- Update module github.com/golang-jwt/jwt/v4
- Update module gopkg.in/yaml.v2 to v3
- Update module gitlab.com/gitlab-org/gitaly/v15 to v16
- Update logrus to v1.9.3
- Update module golang.org/x/sync to v0.2.0
- Update module github.com/pires/go-proxyproto to v0.7.0
- Update module google.golang.org/grpc to v1.55.0
- Update module github.com/prometheus/client_golang to v1.15.1
- Update module github.com/otiai10/copy to v1.11.0
- Make golang 1.20 the default for gitlab-shell development and CI
- Update module golang.org/x/crypto to v0.9.0
- Update dependency golang to v1.20.4
- Update module github.com/hashicorp/go-retryablehttp to v0.7.2

Changelog: other