message: ci: Improve vcpkg binary cache settings
  This change comes with two improvements:
  1) using the VCPKG_DEFAULT_BINARY_CACHE variable drops dependency on
  vcpkg default cached archives location, and improves readability
  2) two obvious cases when binary cache is invalidated are defined, that
  guaranties it won't grow boundlessly when, for example, vcpkg has being
  updated.
diff: @@ -86,6 +86,7 @@ task:
  PATH: 'C:\jom;C:\Python39;C:\Python39\Scripts;C:\Program Files (x86)\Microsoft Visual Studio\2019\BuildTools\MSBuild\Current\Bin;%PATH%'
  PYTHONUTF8: 1
  CI_VCPKG_TAG: '2021.05.12'
  + VCPKG_DEFAULT_BINARY_CACHE: 'C:\Users\ContainerAdministrator\AppData\Local\vcpkg\archives'
  QT_DOWNLOAD_URL: 'https://download.qt.io/official_releases/qt/5.12/5.12.11/single/qt-everywhere-src-5.12.11.zip'
  QT_LOCAL_PATH: 'C:\qt-everywhere-src-5.12.11.zip'
  QT_SOURCE_DIR: 'C:\qt-everywhere-src-5.12.11'
  @@ -121,7 +122,13 @@ task:
  - jom
  - jom install
  vcpkg_binary_cache:
  - folder: 'C:\Users\ContainerAdministrator\AppData\Local\vcpkg\archives'
  + folder: '%VCPKG_DEFAULT_BINARY_CACHE%'
  + reupload_on_changes: true
  + fingerprint_script:
  + - echo %CI_VCPKG_TAG%
  + - msbuild -version
  + populate_script:
  + - mkdir %VCPKG_DEFAULT_BINARY_CACHE%
  install_python_script:
  - choco install --yes --no-progress python3 --version=3.9.6
  - pip install zmq
  