* Tweak greyscale JSON test error message (#78469)
## About The Pull Request
Slightly changes the wording of the greyscale JSON check error.
The previous creates messages such as "Expected 1 but only found 3."
which implies it isn't finding enough, which isn't always the case.
## Changelog
🆑 LT3
spellcheck: Improved wording in greyscale JSON error message
/🆑
* Tweak greyscale JSON test error message
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Co-authored-by: lessthanthree <83487515+lessthnthree@users.noreply.github.com>