Use latest PowerShell version

[mthalman]

Related to #1121 (comment)

Updates installation of PowerShell to get the latest version. This aligns with other Dockerfiles which install PowerShell from PMC, which ends up being the latest version. Right now, the latest version is PowerShell 7.4.

For the Nano Server Dockerfile, PowerShell no longer produces Nano Server images after 7.2. So we need to roll our own.

[mthalman]

These changes fail with this error:

Step 5/9 : COPY --from=mcr.microsoft.com/powershell:windowsservercore-ltsc2022 [ "C:\\Program Files\\PowerShell\\latest\\", "C:\\Program Files\\PowerShell\\" ]
windowsservercore-ltsc2022: Pulling from powershell
invalid from flag value mcr.microsoft.com/powershell:windowsservercore-ltsc2022: a Windows version 10.0.20348-based image is incompatible with a 10.0.17763 host

Of course I can't use the ltsc2022 image from an 1809 machine. Docker Desktop tricked me by making this work locally.

[mthalman]

ping @dotnet/dotnet-docker-reviewers