Temporarily disable ios compile bot

BUG=skia:
TBR=rmistry
NOTRY=true
GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1757053002

Review URL: https://codereview.chromium.org/1757053002
1 file changed