Bump go to 1.21

[CubicrootXYZ]

Describe your changes

Type of change

• Documentation
• New Feature
• Bugfix
• Improvements

Related issue(s)

Test plan

Please provide a test plan so other people can test your code faster

Checklists

Before requesting a review

• I reviewed all of my code changes
• I compiled and executed the code including all changes
• I added documentation for new API endpoints
• All jobs are succeeding
• All Todos in the code done
• There are no other pull requests open for the same issues

For improved code quality we propose those additional steps:

• I added (unit)testing for my changes

Before merging

• Branch is up to date with main
• Changes are tested, reviewed and approved by a maintainer
• Documentation states the newest version number

After merging

• New release published or changes added to draft of next release