download 7z Boost archive on Windows instead of exe

.github/workflows/ci.yaml

@@ -13,6 +13,7 @@ env:
   THREADS: 4
   CONFIG: RelWithDebInfo
   BOOST_ROOT: ${{ github.workspace }}/_boost
+  BOOST_VERSION: 1.74.0
   ALPAKA_BRANCH: 0.9.0
 
 jobs:
@@ -34,7 +35,6 @@ jobs:
     - uses: actions/checkout@v2
     - name: install boost
       run: |
-          BOOST_VERSION=1.74.0
           BOOST_ARCHIVE=boost_${BOOST_VERSION//./_}.tar.bz2
           wget -q https://boostorg.jfrog.io/artifactory/main/release/$BOOST_VERSION/source/$BOOST_ARCHIVE
           tar -xf $BOOST_ARCHIVE
@@ -207,7 +207,6 @@ jobs:
           BOOST_ARCHIVE=boost_${BOOST_VERSION//./_}.tar.bz2
           wget -q https://boostorg.jfrog.io/artifactory/main/release/$BOOST_VERSION/source/$BOOST_ARCHIVE
           tar -xf $BOOST_ARCHIVE
-          rm $BOOST_ARCHIVE
           mv boost_${BOOST_VERSION//./_} "${BOOST_ROOT}"
       - name: install extras
         if: ${{ matrix.install_extra }} 
@@ -273,10 +272,12 @@ jobs:
     - uses: actions/checkout@v2
     - name: install boost
       run: |
-        # From: https://github.com/actions/virtual-environments/issues/2667
-        $url = "https://sourceforge.net/projects/boost/files/boost-binaries/1.74.0/boost_1_74_0-msvc-14.1-64.exe"
-        (New-Object System.Net.WebClient).DownloadFile($url, "$env:TEMP\boost.exe")
-        Start-Process -Wait -FilePath "$env:TEMP\boost.exe" "/SILENT","/SP-","/SUPPRESSMSGBOXES","/DIR=$env:BOOST_ROOT"
+        $BOOST_ARCHIVE = "boost_$($env:BOOST_VERSION.replace('.', '_')).7z"
+        $url = "https://boostorg.jfrog.io/artifactory/main/release/$env:BOOST_VERSION/source/$BOOST_ARCHIVE"
+        (New-Object System.Net.WebClient).DownloadFile($url, "$env:TEMP/boost.7z")
+        7z x "$env:TEMP/boost.7z" -o"$env:TEMP"
+        ls $env:TEMP
+        mv "$env:TEMP/boost_$($env:BOOST_VERSION.replace('.', '_'))" "$env:BOOST_ROOT"
     - name: vcpkg install dependencies
       run: |
         vcpkg install catch2 fmt vc tinyobjloader