Run Golang 1.21 by default and update outstanding packages

[outductor]

Some old libs had the following problems

• https://avd.aquasec.com/nvd/2023/cve-2023-39325/
• https://github.com/advisories/GHSA-m425-mq94-257g

[outductor]

@chihyuwu Can you please take a look?