Fix: Retrieving dotnet runtimes hangs when there are too many runtimes installed

[Booksbaum]

Test Main tests.can get runtimes hangs on my PC.

Reason: ProjInfo calls dotnet --list-runtimes by executing dotnet, waiting for it to finish, and then reading the output:

proj-info/src/Ionide.ProjInfo/Library.fs

Lines 25 to 40 in 1c9317b

	let private execDotnet (cwd: DirectoryInfo) (binaryFullPath: FileInfo) args =
	let info = ProcessStartInfo()
	info.WorkingDirectory <- cwd.FullName
	info.FileName <- binaryFullPath.FullName
	for arg in args do
	info.ArgumentList.Add arg
	info.RedirectStandardOutput <- true
	let p = System.Diagnostics.Process.Start(info)
	p.WaitForExit()
	seq {
	while not p.StandardOutput.EndOfStream do
	yield p.StandardOutput.ReadLine()
	}

Important: First Waiting for exit, Then reading output

But: The executing Process blocks when its output buffer is full and not read (see Remarks for Process.StandardOutput).
-> When there are too many runtimes installed (-> too many lines from --list-runtimes), calling dotnet --list-runtimes hangs.

I installed at least one new dotnet version over the last days (-> several additional runtimes). Which seems to just crossed the line between "working" and "buffer full"
(there are more runtimes than sdks -> happend with --list-runtimes, not (yet) with --list-sdks)

Fix: Read lines while executing

[baronfel]

This makes good sense 👍 Thanks for this change.