bump tsa chart for timestamp-server v1.2.3 release

[bobcallaway]

Description of the change

Existing or Associated Issue(s)

Additional Information

Checklist

• [ ] Chart version bumped in Chart.yaml according to semver. Where applicable, update and bump the versions in any associated umbrella chart
• [ ] Variables are documented in the values.yaml and added to the README.md. The helm-docs utility can be used to generate the necessary content. Use helm-docs --dry-run to preview the content.
• [ ] JSON Schema generated.
• [ ] List tests pass for Chart using the Chart Testing tool and the ct lint command.