[3.14] gh-140189: Add CI job to test iOS builds. (GH-140190) (#140696)

Adds a CI configuration to test iOS builds on every build.
(cherry picked from commit f4e6370582380b12286b6f5b625c282eaf12c84a)

Co-authored-by: Russell Keith-Magee <russell@keith-magee.com>
Co-authored-by: Hugo van Kemenade <1324225+hugovk@users.noreply.github.com>