Fixing problem on Linux where dotnet run fails because we try to set an IIS config

[nul800sebastiaan]

This is a follow up on #17886 which, after some discussion, seemed like a bad idea as there was a small possibility that we would break behavior that package developers might rely on.

Instead of not setting the global config, this catches errors while adding global rule to allow synchronous IO for IIS only (Kestrel one should run anywhere regardless, so I've kept it as it was before).

This has been tested on a Ubuntu machine with the apt package manager using these 3 commands:

sudo apt-get update && \
  sudo apt-get install -y dotnet-sdk-9.0

sudo apt-get update && \
  sudo apt-get install -y aspnetcore-runtime-9.0

sudo apt-get install -y dotnet-runtime-9.0

Installing Umbraco as described in the documentation would fail with a TypeLoaderException before this change:

After this fix it runs like it should:

Notes

• I only put the configuration options for IIS in a try/catch - it never failed on Kestrel and I don't see why it would, Kestrel is fully supported on Windows as well
• Had to use a little workaround to get the try/catch to actually work, by deferring the setting of the option to a new method (as found by @AndyButland in this SO post: https://stackoverflow.com/a/3346975)
• I've left the obsoletion message in there, I think it's a good idea to remove this global override as soon as possible. I've set it to v17 for now, but should it be for v16?

[AndyButland]

Looks good, but agree the obsolete can reference 16 and I left a couple of comments inline.