Add missing Icelandic character í (VK_I) (#46424)

## Summary of the Pull Request
The Icelandic language definition was missing `í` entirely. This adds it
to `VK_I`.

Closes: Add missing Icelandic character í (VK_I) #46423

## Validation Steps Performed
Code review only. The change is a single line addition to a data-only
switch statement, consistent in structure with all other language
entries in the file. No binaries, pipelines, or localization files are
affected.