Workflow job execution doc edited to clarify that 'env' context is not available in job 'if' conditional

[OlayinkaAtobiloye]

Why:

Closes #21927, #17099

What's being changed (if available, include any code snippets, screenshots, or gifs):

Check off the following:

• I have reviewed my changes in staging (look for the "Automatically generated comment" and click the links in the "Preview" column to view your latest changes).
• For content changes, I have completed the self-review checklist.

[OlayinkaAtobiloye]

Hi, @cmwilson21! I raised a PR addressing a workflow job execution, could you please check it out when chanced? Thanks!

[github-actions]

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This comment is automatically generated and will be overwritten every time changes are committed to this branch.

The table contains an overview of files in the content directory that have been changed in this pull request. It's provided to make it easy to review your changes on the staging site. Please note that changes to the data directory will not show up in this table.

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Content directory changes

You may find it useful to copy this table into the pull request summary. There you can edit it to share links to important articles or changes and to give a high-level overview of how the changes in your pull request support the overall goals of the pull request.

Source	Preview	Production	What Changed
account-and-profile/setting-up-and-managing-your-personal-account-on-github/managing-personal-account-settings/changing-your-github-username.md	fpt ghec ghes@ 3.8 3.7 3.6 3.5 3.4	fpt ghec ghes@ 3.8 3.7 3.6 3.5 3.4
actions/using-jobs/using-conditions-to-control-job-execution.md	fpt ghec ghes@ 3.8 3.7 3.6 3.5 3.4 ghae	fpt ghec ghes@ 3.8 3.7 3.6 3.5 3.4 ghae

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fpt: Free, Pro, Team
ghec: GitHub Enterprise Cloud
ghes: GitHub Enterprise Server
ghae: GitHub AE

[cmwilson21]

@OlayinkaAtobiloye great work! I'll get this triaged for review! ⚡

[OlayinkaAtobiloye]

self-review checklist.

Hi @Esiakha, it is now completed!

[hubwriter]

@OlayinkaAtobiloye - Many thanks for making these documentation changes - much appreciated. 🙇

I've made a few small changes, just to keep things in line with our style guide.

I'll get this merged/published.

Thanks again for contributing to the docs.
🚀

[github-actions]

Thanks very much for contributing! Your pull request has been merged 🎉 You should see your changes appear on the site in approximately 24 hours. If you're looking for your next contribution, check out our help wanted issues ⚡

[avalosriveraamericacitlali-cell]

Por qué:

Cierra los números #41927 y #170.

¿Qué se va a cambiar? (Si es posible, incluya fragmentos de código, capturas de pantalla o GIF):

Marque las siguientes casillas:

• He revisado mis cambios en el entorno de pruebas (busca el comentario "Comentario generado automáticamente" y haz clic en los enlaces de la columna "Vista previa" para ver tus últimos cambios).
• Para los cambios de contenido, he completado la lista de verificación de autoevaluación .