actions(concurrency): fix typo

[amithm7]

Why:

To cancel workflows in same concurrency group, cancel-in-progress: true option is needed.

Currently docs state, "will be cancelled" which implies it as default behavior, although it is not.

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

"will be cancelled" -> "can be cancelled"

Check off the following:

• [x] 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).
• [x] For content changes, I have completed the self-review checklist.

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[cmwilson21]

@amithm7 Thanks so much for opening a PR! I'll get this triaged for review :zap:

[skedwards88]

Thanks for opening this issue! You are correct that you must specify cancel-in-progress: true in order to cancel any job/workflow that is currently running. However, any pending jobs/workflows should be canceled by default. With that distinction in mind, I'm going to close this PR, but I hope to see more contributions from you in the future! If you feel that I am mistaken or misunderstood you, feel free to open an issue and we can discuss more.