Provisioning: Use Docker registry when pulling images in macOS

Task-number: QTQAINFRA-5428
Pick-to: 6.4
Change-Id: I0034922dd7cc42b55b3c1e852070df29a54c529b
Reviewed-by: Jani Heikkinen <jani.heikkinen@qt.io>

coin/provisioning/common/macos/docker.sh

@@ -61,3 +61,14 @@ DownloadURL $urlCache $urlOccifical $sha "/tmp/Docker_${chip}.dmg"
 sudo hdiutil attach "/tmp/Docker_${chip}.dmg"
 sudo /Volumes/Docker/Docker.app/Contents/MacOS/install --accept-license --user qt
 sudo hdiutil detach /Volumes/Docker
+
+# Add registry mirror for docker images
+mkdir "$HOME/.docker"
+sudo tee -a $HOME/.docker/daemon.json <<"EOF"
+{
+        "builder": { "gc": { "defaultKeepStorage": "20GB", "enabled": true } },
+        "experimental": false,
+        "features": { "buildkit": true },
+        "registry-mirrors": ["http://repo-clones.ci.qt.io:5000"]
+}
+EOF