Correct check for SERPAPI key

[LukasWallrich]

Description

Fixes # (issue)

Type of Change

• Documentation/Contents/grammar update
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Bug fix (non-breaking change which fixes an issue)

How Has This Been Tested?

• Tested Locally
• Manual review / previewed on staging.forrt.org content/webpage changes
• Not Tested yet

Checklist for Content Editors and Non-Developers

• The content is clear, accurate, and follows community guidelines.
• All updated content has been previewed on the staging site.
• All links, references, and formatting have been checked for correctness.
• The change aligns with the overall style and communication goals.
• No broken links in text/content

Checklist for Developers:

• I have attempted to stay aligned to related code in this repository rather than reinventing the wheel.
• I have performed a self-review of my own code.
• I have commented my code, particularly in hard-to-understand areas.
• I have made corresponding changes to the documentation.
• My changes generate no new warnings.

Additional Notes

[github-actions]

👍 All image files/references (if any) are in webp format, in line with our policy.

[richarddushime]

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