Runners failing because of docker permissions

[jayanthvn]

What type of PR is this?
Bug

Which issue does this PR fix:

Run docker image prune -f
Got permission denied while trying to connect to the Docker daemon socket at unix:///var/run/docker.sock: Post http://%2Fvar%2Frun%2Fdocker.sock/v1.40/images/prune?filters=%7B%22dangling%22%3A%7B%22true%22%3Atrue%7D%7D: dial unix /var/run/docker.sock: connect: permission denied
Error: Process completed with exit code 1.

What does this PR do / Why do we need it:
Added sudo to docker image prune.

If an issue # is not available please add repro steps and logs from IPAMD/CNI showing the issue:

Testing done on this change:

Have scheduled a run.

Automation added to e2e:

n/a

Will this break upgrades or downgrades. Has updating a running cluster been tested?:
No

Does this change require updates to the CNI daemonset config files to work?:

No

Does this PR introduce any user-facing change?:

No

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.