Remove cached directories and associated script blocks from appveyor CI configuration.

.appveyor.yml

@@ -5,8 +5,6 @@ configuration: Release
 platform: x64
 clone_depth: 5
 environment:
-  APPVEYOR_SAVE_CACHE_ON_ERROR: true
-  CLCACHE_SERVER: 1
   PATH: 'C:\Python37-x64;C:\Python37-x64\Scripts;%PATH%'
   PYTHONUTF8: 1
   QT_DOWNLOAD_URL: 'https://github.com/sipsorcery/qt_win_binary/releases/download/v1.6/Qt5.9.8_x64_static_vs2019.zip'
@@ -14,45 +12,31 @@ environment:
   QT_LOCAL_PATH: 'C:\Qt5.9.8_x64_static_vs2019'
   VCPKG_INSTALL_PATH: 'C:\tools\vcpkg\installed'
   VCPKG_COMMIT_ID: 'ed0df8ecc4ed7e755ea03e18aaf285fd9b4b4a74'
-cache:
-- C:\tools\vcpkg\installed -> build_msvc\vcpkg-packages.txt
-- C:\Qt5.9.8_x64_static_vs2019
 install:
 # Disable zmq test for now since python zmq library on Windows would cause Access violation sometimes.
 # - cmd: pip install zmq
 # Powershell block below is to install the c++ dependencies via vcpkg. The pseudo code is:
-# 1. Check whether the vcpkg install directory exists (note that updating the vcpkg-packages.txt file
-#    will cause the appveyor cache rules to invalidate the directory)
-# 2. If the directory is missing:
 #    a. Checkout the vcpkg source (including port files) for the specific checkout and build the vcpkg binary,
 #    b. Install the missing packages.
 - ps: |
       $env:PACKAGES = Get-Content -Path build_msvc\vcpkg-packages.txt
-      Write-Host "vcpkg list: $env:PACKAGES"
-      if(!(Test-Path -Path ($env:VCPKG_INSTALL_PATH))) {
+      Write-Host "vcpkg installing packages: $env:PACKAGES"
       cd c:\tools\vcpkg
       $env:GIT_REDIRECT_STDERR = '2>&1' # git is writing non-errors to STDERR when doing git pull. Send to STDOUT instead.
-          git pull origin master
-          git checkout $env:VCPKG_COMMIT_ID
-          .\bootstrap-vcpkg.bat
+      git pull origin master > $null
+      git -c advice.detachedHead=false checkout $env:VCPKG_COMMIT_ID
+      .\bootstrap-vcpkg.bat > $null
       Add-Content "C:\tools\vcpkg\triplets\$env:PLATFORM-windows-static.cmake" "set(VCPKG_BUILD_TYPE release)"
       .\vcpkg install --triplet $env:PLATFORM-windows-static $env:PACKAGES.split() > $null
+      Write-Host "vcpkg packages installed successfully."
+      .\vcpkg integrate install
       cd "$env:APPVEYOR_BUILD_FOLDER"
-      }
-      else {
-        Write-Host "required vcpkg packages already installed."
-      }
-      c:\tools\vcpkg\vcpkg integrate install
 before_build:
 # Powershell block below is to download and extract the Qt static libraries. The pseudo code is:
-# 1. If the Qt destination directory exists assume it is correct and do nothing. To
-#    force a fresh install of the packages delete the job's appveyor cache.
-# 2. Otherwise:
 #    a. Download the zip file with the prebuilt Qt static libraries.
 #    b. Check that the downloaded file matches the expected hash.
 #    c. Extract the zip file to the specific destination path expected by the msbuild projects.
 - ps: |
-      if(!(Test-Path -Path ($env:QT_LOCAL_PATH))) {
       Write-Host "Downloading Qt binaries.";
       Invoke-WebRequest -Uri $env:QT_DOWNLOAD_URL -Out qtdownload.zip;
       Write-Host "Qt binaries successfully downloaded, checking hash against $env:QT_DOWNLOAD_HASH...";
@@ -64,10 +48,6 @@ before_build:
         Write-Host "ERROR: Qt binary download did not match the expected hash.";
         Exit-AppveyorBuild;
       }
-      }
-      else {
-         Write-Host "Qt binaries already present.";
-      }
 - cmd: python build_msvc\msvc-autogen.py
 build_script:
 - cmd: msbuild /p:TrackFileAccess=false build_msvc\bitcoin.sln /m /v:q /nologo