Using time.Timers instead of time.After()

[arschles]

As explained in the docs for time.After(), the time.Timer that underpins the call to time.After is not released and recovered by the GC. This PR fixes the resulting leak by creating and releasing time.Timers instead of using time.After()

Checklist

• Commits are signed with Developer Certificate of Origin (DCO - learn more)
• Tests have been added
• (N/A) A PR is opened to update our Helm chart (repo) (if applicable, ie. when deployment manifests are modified)
• (N/A) A PR is opened to update the documentation on (repo) (if applicable)
• Changelog has been updated

[zroubalik]

Thanks a lot for this!