fix(client): Update misspelled word "backgrounds"

[Rabberpoli]

Fixed "backgrouns" into "backgrounds"

Checklist:

• [x ] I have read and followed the contribution guidelines.
• [x ] I have read and followed the how to open a pull request guide.
• [ x] My pull request targets the main branch of freeCodeCamp.
• I have tested these changes either locally on my machine, or GitPod.

Closes #54204

[gikf]

Note for future - it is recommended to make changes on a separate branch, rather than the main branch. See more about it in point 3 at https://contribute.freecodecamp.org/#/how-to-contribute-to-the-codebase?id=contributing-to-the-codebase.

[jdwilkin4]

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We look forward to future contributions. 👍