Fix illustration paths in survey response page

What does this MR do and why?

This is a follow up for !71809 (merged).

It fixes the paths for the illustrations (introduced in MR) used in the survey response page.

Screenshots or screen recordings

Before	After

How to set up and validate locally

1. Ensure :calendly_invite_link feature flag is enabled

   # rails console
   Feature.enable(:calendly_invite_link)

2. Visit http://localhost:3000/-/survey_responses?show_invite_link=true&show_incentive=true and verify that both new illustrations are shown correctly
   Click to expand

   

MR acceptance checklist

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• I have evaluated the MR acceptance checklist for this MR.