Bump maccore to get update to bot provisioning. (#5727)

* Bump maccore to get update to bot provisioning.

Diff: 3105682752...f3034c261f

* [jenkins] Prepackaged macOS tests only need a custom keychain.

jenkins/prepare-packaged-macos-tests.sh

@@ -90,4 +90,4 @@ fi
 git reset --hard "$MACCORE_HASH"
 cd ..
 
-./maccore/tools/install-qa-provisioning-profiles.sh
+./maccore/tools/install-qa-provisioning-profiles.sh --only-create-keychain

mk/xamarin.mk

@@ -1,5 +1,5 @@
 ifdef ENABLE_XAMARIN
-NEEDED_MACCORE_VERSION := 31056827520ecc8e932ffbc7e87975e31b922012
+NEEDED_MACCORE_VERSION := f3034c261f70c980f75d8d89ccf711d0814907f8
 NEEDED_MACCORE_BRANCH := master
 
 MACCORE_DIRECTORY := maccore