Treetop v0.1.0-2

ci(release): use Windows PowerShell, not pwsh, on the self-hosted runner

The Windows staging step set `shell: pwsh`, but the self-hosted Windows
runner only has Windows PowerShell 5.1 (`powershell`) — PowerShell Core
(`pwsh`) isn't installed, so the step failed with "pwsh: command not
found". The cmdlets used all exist in 5.1 and the script is ASCII, so
`powershell` runs it unchanged.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>