Remove the now unneeded `shrink-to-fit` directive.

Redo #27818.

shrink-to-fit=no is not needed anymore - Apple removed the need for it from iOS9.3 onwards

See https://www.scottohara.me/blog/2018/12/11/shrink-to-fit.html and https://github.com/h5bp/html5-boilerplate/issues/2102

Do we plan to also bump the minimum iOS version @mdo?

Fixes #27861 (closed)