Fix output spelling of cancelled

[KMiller-Grafana]

PR #5297 introduced msg output with an alternate spelling of "cancelled" that only had 1 'l' and not two. This meant that some messages used "canceled" and others used "cancelled." This PR changes all spellings to be "cancelled."

I specifically did not change function/method name or variable spellings. Just the strings.

[vlad-diachenko]

Hi @KMiller-Grafana . this error message canceled (with 1 l) comes from built-in golang libraries and from GRPC module. I do not think that we can change it...
Also, we can fix the text exact in this test file, however, errors in runtime will be with 1 l anyway.
if it's critical, we can try to analyse how to fix it. What do you think?

[KMiller-Grafana]

Thanks, @vlad-diachenko. I didn't realize that these strings were matched against ones with a different spelling. I'll close the PR, as there's nothing to fix.