Python: Unset proxy for python pip cert issues

Task-number: QTQAINFRA-6473
Pick-to: 6.7
Change-Id: I43cfd0cba3fcdcd7acdf1d75ee2347dac8b77175
Reviewed-by: Dimitrios Apostolou <jimis@qt.io>
(cherry picked from commit 31774f9103)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>

coin/provisioning/common/windows/set-proxy.ps1

@@ -5,6 +5,9 @@ $n = Get-Content "$PSScriptRoot\..\shared\http_proxy.txt"
 $n = $n.Split('=')
 New-Variable -Name $n[0] -Value $n[1]
 
+Write-Host "Temporarily not setting proxy" # QTQAINFRA-6473
+$proxy = ""
+
 if ([string]::IsNullOrEmpty($proxy)) {
     Write-Host "No proxy is defined."
 } else {