self-hosted-runner: run the Actions runner under the SYSTEM account

Previously, the Actions runner was run under the `NT AUTHORITY\NETWORK
SERVICE` account, which lacks the permissions to install Git for
Windows. However, that is precisely what the `git-artifacts` workflow
is supposed to do.

Tweaking the `./config.cmd` invocation by adding `--windowslogonaccount
"NT AUTHORITY\SYSTEM"`` fixes the issue.

Signed-off-by: Dennis Ameling <[email protected]>
Signed-off-by: Johannes Schindelin <[email protected]>

Author: dennisameling

azure-self-hosted-runners/post-deployment-script.ps1

@@ -275,7 +275,7 @@ If ($Ephemeral -ne 'true') {
 }
 
 Write-Output "Configuring the runner"
-cmd.exe /c "${GitHubActionsRunnerPath}\config.cmd" --unattended $EphemeralOption --name ${GithubActionsRunnerName} --runasservice --labels $($GitHubAction.RunnerLabels) --url ${GithubActionsRunnerRegistrationUrl} --token ${GitHubActionsRunnerToken}
+cmd.exe /c "${GitHubActionsRunnerPath}\config.cmd" --unattended $EphemeralOption --name ${GithubActionsRunnerName} --windowslogonaccount "NT AUTHORITY\SYSTEM" --runasservice --labels $($GitHubAction.RunnerLabels) --url ${GithubActionsRunnerRegistrationUrl} --token ${GitHubActionsRunnerToken}
 
 # Ensure that the service was created. If not, exit with error code.
 if ($null -eq (Get-Service -Name "actions.runner.*")) {