Some dependencies have open vulnerabilities - chi and mapstructure need updates

[gcemaj]

Hey! I noticed that some of the dependencies in ko have open vulnerabilities. Mainly:

github.com/go-chi/chi@v4.1.2+incompatible - has 1 known vulnerability (GO-2025-3770)
github.com/go-viper/mapstructure/v2@v2.2.1 - has 4 known vulnerabilities (GHSA-fv92-fjc5-jj9h, GO-2025-3787, GHSA-2464-8j7c-4cjm, GO-2025-3900)

Could you update these to newer versions that patch these issues?

Thanks!