Remove go toolchain in go.mod

[dehanj]

Description

Removes the toolchain statement in the go.mod file

Type of change

Please tick any that are relevant to this PR and remove any that aren't.

• Bugfix (non breaking change which resolve an issue)

Submission checklist

• My code follows the style guidelines of this project
• I have performed a self-review of my changes
• My changes are well written and CI is passing
• I have squashed my work to relevant commits and rebased on main for linear history
• I have added a "Co-authored-by: x" if several people contributed, either pair programming or by squashing commits from different authors.

[mchack-work]

LGTM.