env/windows-arm64: disable builder password expiration

The builder's Windows account password is just "gopher"
because the machine is secured via other means, and so
the password need not expire every 42 days.

Fixes golang/go#51546.

Change-Id: I65f804d33de5bca14527757d23c3a1980bfb7759
Reviewed-on: https://go-review.googlesource.com/c/build/+/391358
Reviewed-by: Heschi Kreinick <heschi@google.com>
Trust: Dmitri Shuralyov <dmitshur@golang.org>
diff --git a/env/windows-arm64/startup.ps1 b/env/windows-arm64/startup.ps1
index 88e343c..6cc75c4 100644
--- a/env/windows-arm64/startup.ps1
+++ b/env/windows-arm64/startup.ps1
@@ -143,6 +143,7 @@
 $buildlet_password = "gopher"
 net user $buildlet_user $buildlet_password /ADD
 net localgroup administrators $buildlet_user /ADD
+Set-LocalUser -Name $buildlet_user -PasswordNeverExpires $true
 
 # Run the bootstrap program on login
 Write-Host "setting stage0 to run on start"