fix: remove prettier-ignore line from curriculum-file-structure

[MatyiFKBT]

Removed the extra prettier-ignore line which in its current form does nothing.

I ran astro check and the lint task as well:

> prettier . --check --cache && eslint . --cache

Checking formatting...
All matched files use Prettier code style!
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Checklist:

• I have read freeCodeCamp's contribution guidelines.
• My pull request has a descriptive title (not a vague title like Update index.md)

Left: old version, right: proposed