(build) Remove AutoHotKey Install from AppVeyor

The dependencies introduced by AutoHotKey v1 were causing some builds to fail without good cause, e.g. when it was upgraded.

Removing it shouldn't increase build times _too_ much, but allow some builds to succeed.

.appveyor.yml

@@ -61,7 +61,6 @@ install:
       'chocolatey' = $chocoVersion
       'wormies-au-helpers' = '0.4.1'
       'chocolatey-core.extension' = '1.4.0'
-      'autohotkey.install' = '1.1.35.00'
       'chocolatey-community-validation.extension' = '0.1.0'
     }.GetEnumerator() | % {
       if (!(Test-Path "${env:nupkg_cache_path}\$($_.Key).$($_.Value).nupkg")) { rm "${env:nupkg_cache_path}\$($_.Key).*.nupkg" ; Invoke-WebRequest "https://chocolatey.org/api/v2/package/$($_.Key)/$($_.Value)" -OutFile "${env:nupkg_cache_path}\$($_.Key).$($_.Value).nupkg" }