Merge #21112: ci: use Focal for macOS cross builds

ac24af453d ci: use Ubuntu Focal for macOS cross build (fanquake)

Pull request description:

  I had assumed Cirrus was spinning up Docker containers to run the CI,
  however we are actaully running on the Cirrus machines themselves. See
  `DANGER_RUN_CI_ON_HOST` and in the logs:
  ```bash
  Running on host system without docker wrapper
  ```

  So with this change we will actually be using Focal for the macOS cross build.

  Follow up to #21036.

  This originally contained Windows changes, and an attempt to get Cirrus running without `DANGER_RUN_CI_ON_HOST`, however that seems non-trival, so Windows changes have been dropped from here for now.

ACKs for top commit:
  MarcoFalke:
    cr ACK ac24af453d

Tree-SHA512: 587ba5acf741bcefecf1bc262fa1177f565ebfa9de56125eca19ed3c7db7b9aabfb96866e9c140681b88cb7015a3ded2bc6b4b1b235543d6f6e9dfc6984d569f

.cirrus.yml

@@ -160,10 +160,10 @@ task:
     FILE_ENV: "./ci/test/00_setup_env_native_nowallet.sh"
 
 task:
-  name: 'macOS 10.14 [gui, no tests] [bionic]'
+  name: 'macOS 10.14 [gui, no tests] [focal]'
   << : *GLOBAL_TASK_TEMPLATE
   container:
-    image: ubuntu:bionic
+    image: ubuntu:focal
   env:
     FILE_ENV: "./ci/test/00_setup_env_mac.sh"
 

ci/test/00_setup_env_mac.sh

@@ -9,7 +9,7 @@ export LC_ALL=C.UTF-8
 export CONTAINER_NAME=ci_macos_cross
 export DOCKER_NAME_TAG=ubuntu:20.04  # Check that Focal can cross-compile to macos (Focal is used in the gitian build as well)
 export HOST=x86_64-apple-darwin18
-export PACKAGES="cmake imagemagick libcap-dev librsvg2-bin libz-dev libbz2-dev libtiff-tools python3-dev python3-setuptools xorriso"
+export PACKAGES="cmake imagemagick libcap-dev librsvg2-bin libz-dev libbz2-dev libtiff-tools libtinfo5 python3-dev python3-setuptools xorriso"
 export XCODE_VERSION=11.3.1
 export XCODE_BUILD_ID=11C505
 export RUN_UNIT_TESTS=false