Verify the published Python compatibility version

[tianon]

This asks PyPy to tell us which version of Python it is so we can validate that we're claiming the correct one.

This is related to 94d8ce9, but the impact is 100% superficial (and only exhibits in a comment in our Dockerfiles, in fact), so I'm not actually convinced this makes any sense to go forward with, but figured I'd open it for discussion (since it's really trivial for us to verify).

[tianon]

Whew, https://github.com/moby/moby/blob/65c2f799b4f9d839fb8d4b550a2459b17166925c/builder/dockerfile/dispatchers_windows.go#L117-L129 is not a rabbit hole I wanted to dig into today, but here I am -- that's all valid for cmd.exe, but notably not for powershell.exe, so that's why we're losing double quotes.

[tianon]

Reading through https://learn.microsoft.com/en-us/dotnet/csharp/fundamentals/program-structure/main-command-line (and clicking down/through to https://learn.microsoft.com/en-us/dotnet/api/system.environment.commandline?view=net-9.0#system-environment-commandline), there is an API that PowerShell could use to extract the original Windows "CommandLine" value and parse it differently (ie, like cmd.exe does), but they'd have to go way out of their way to do so, and it wouldn't be compatible with any of their existing argument parsing, and would be Windows-specific behavior/parsing, so I really doubt this is something they'd ever consider. 😭

[tianon]

Arguably, Moby/Docker should only be applying that block if we're invoking cmd.exe 🤦

[yosifkit]

🤔While it is nice to verify the data we get from downloads.python.org/pypy/versions.json, this one isn't material for the provided binaries and is just for a comment in the Dockerfile. I don't think it isn't worth failing the automated update.sh build if it is wrong.

[tianon]

Agreed, we can resurrect this if we ever change our mind (or use that provided version for anything more serious than a comment).