Attempt to fix the VC redist installation issues

- Try to avoid comparing against a hash from when the installer was built, since MS frequently updates the redist installer from that link. The normal signature verification can be used
- Remove caching of the redist for the CI builds, since this resulted in it never being updated.

#305

.github/workflows/build.yml

@@ -82,15 +82,7 @@ jobs:
 
     - uses: microsoft/[email protected]
 
-    - name: Cache VC redist
-      id: cache-redist
-      uses: actions/cache@v2
-      with:
-        path: installer/windows/redist/vc_redist.x64.exe
-        key: ${{ runner.os }}-redist-v1
-
     - name: Fetch VC redist
-      if: steps.cache-redist.outputs.cache-hit != 'true'
       run: |
         cd installer/windows
         mkdir redist

installer/windows/installer.wxs

@@ -21,6 +21,7 @@
 
     <Chain>
       <!-- VS2015 Redistributable. -->
+      <!-- Use SuppressSignatureVerification=no instead of hashing, since the VC redist URL is frequently updated by Microsoft. -->
       <ExePackage Id="vcredist"
           DisplayName="$(var.VCRedistName)"
           Cache="no"
@@ -31,6 +32,7 @@
           SourceFile="$(var.VCRedistFile)"
           DownloadUrl="$(var.VCRedistURL)"
           InstallCommand="/quiet /norestart"
+          SuppressSignatureVerification="no"
           DetectCondition="vcredist AND (vcredist &gt;= &quot;14.26.28720&quot;)">
       </ExePackage>