Use `-NoProfile` for suggested powershell install command

We should specify `-NoProfile` in the suggested powershell install command.

This was suggested in astral-sh/uv#10299, with the following explanation:

> `-NoProfile` (appreviated to `-NoP`) is used as the profile can interfere with the intended operation

~~None of us are familiar enough with PowerShell to know if there's any problems with using it, so we should look into it and if everything looks good start using it.~~

(**NOTE:** We've decided to explicitly not use abbreviated flags for PowerShell commands.)

No file or test is named. Search the repository for the suggested PowerShell install command, verify how profiles affect it and whether the full -NoProfile flag is appropriate, then update the suggestion and confirm the resulting command uses that flag without abbreviation.

Written by the indexing model from the issue text.