Summary
This PR fixes an issue where Python virtual environments (venv, uv, etc.) were not automatically activated when opening a terminal using PowerShell 7.

Details
ShellKind distinguishes between the legacy Windows PowerShell (ShellKind::PowerShell) and the newer PowerShell 7 (ShellKind::Pwsh). Previously, the logic in resolve_venv_activation_scripts only checked for ShellKind::PowerShell, causing activate.ps1 resolution to fail for Pwsh users.
This change adds ShellKind::Pwsh to the resolution list, mapping it to activate.ps1 just like the legacy PowerShell.

Release Notes:

• Fixed Python virtual environments not automatically activating in PowerShell 7