Update running-k6.md - removed extra "run" arg in cloud k6 bash command

[sparshrestha]

Cloud: the test runs on Grafana Cloud k6 command is incorrect.

What?

k6 cloud run script.js gives following error: ERRO[0000] accepts 1 arg(s), received 2: arg should either be "-", if reading script from stdin, or a path to a script file

correct command to test run on Cloud k6 should exclude the arg run with only: k6 cloud script.js

Checklist

• [x] I have used a meaningful title for the PR.

• [x] I have described the changes I've made in the "What?" section above.

• [x] I have performed a self-review of my changes.

• [x] I have reflected my changes in the docs/sources/v{most_recent_release} folder of the documentation.

[CLAassistant]

All committers have signed the CLA.

[heitortsergent]

@sparshrestha thanks for opening the PR!

The k6 cloud run command is a new option that was introduced in k6 v0.53. Can you please double-check that that's the version you're running?