Search function is sensitive to special characters

I wanted to check whether there were articles on KH about El Niño, and couldn't find any on the search "Nino"

However, I got results when I used "Niño" with a tilde-n

No files or tests are named. Locate the search entry point and inspect how accented characters are compared, then reproduce the reported difference between “Nino” and “Niño”. Done means searches for both forms return the same relevant articles, with regression coverage for the reported example.

Written by the indexing model from the issue text.