Bump validator from 13.15.15 to 13.15.20 in /app in the npm_and_yarn group across 1 directory (#854)

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]