Removed duplication of ${exec.instance.iterationsCompleted}

[InRiPa]

Hi,

just a small update.
In k6-docs/src/data/markdown/translated-guides/en/02 Using k6/12 Execution context variables.md,
Line 47 and 49 are the same.

[CLAassistant]

All committers have signed the CLA.

[taylorflatt]

@InRiPa - There is a automatic PR template that is super helpful for making sure the changes have been made to the right places and tested.

If you're still interested in making this change, it will need to be updated in the doc/sources directories as well.

[InRiPa]

What?

just a small update.
In k6-docs/src/data/markdown/translated-guides/en/02 Using k6/12 Execution context variables.md,
Line 47 and 49 are the same.

Additionally, I went through all versions in docs/sources/k6/*. I think, I caught all instances of it.

Branch is rebased to current version.

Checklist

• I have used a meaningful title for the PR.
• I have described the changes I've made in the "What?" section above.
• I have performed a self-review of my changes.
• I have run the npm start command locally and verified that the changes look good.
  • Couldn't get it to work. I used the Docker file to build and run the project
  • I believe, this is not the intended use. E.g. using

      $ podman build -f Dockerfile -t k6-docs .
      $ podman run -it -p 8000:8000 --rm localhost/k6-docs:latest

• I have made my changes in the docs/sources/k6/next folder of the documentation.
  • see docs/sources/k6/next/using-k6/execution-context-variables.md
• I have reflected my changes in the docs/sources/v{most_recent_release} folder of the documentation.
  • adjusted same line in v0.47 to v0.54
• I have reflected my changes in the relevant folders of the two previous k6 versions of the documentation (if still applicable to previous versions).

Related PR(s)/Issue(s)

none