CI: Rename iOS aarch64 to arm64

Thats what the triplet is expected to be and the script
accepts arm64 too.
Status Job ID Name Coverage
  Build
canceled #321024
amd64 docker
android-arm

canceled #321025
amd64 docker
android-arm64

canceled #321026
amd64 docker
android-x86

canceled #321027
amd64 docker
android-x86_64

canceled #321021
amd64 docker
debian

canceled #321023
macos
ios-arm64

canceled #321022
macos
macos

canceled #321018
amd64 docker
win32

canceled #321019
amd64 docker
win64

canceled #321020
amd64 docker
win64-llvm