Docs: Correct the word sprint to iteration

[kashiwachen]

Code of Conduct

• [X] I have read and agree to the GitHub Docs project's Code of Conduct

What article on docs.github.com is affected?

project-filters.md is gonna be affectet

What part(s) of the article would you like to see updated?

the document is using the word iteration instead of sprint, which makes the example(sprint:@current) not working.

Additional information

Simply change the example to interation:@current

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[cmwilson21]

@kashiwachen Thanks for opening an issue and PR! ⚡