Reduce size and complexity, enhance cross-platform compatibility, update yamldotnet, update test platforms

[GruberMarkus]

This PR contains the following:

• Switch from netstandard2.1 and net47 to only netstandard2.0.
  • This ensures maximum compatibility across Windows PowerShell 5.1 and PowerShell 7 on macOS, Linux and Windows.
  • It reduces code complexity and reduces the total module size.
• Update yamldotnet to the latest release, which is 16.3.0.
• Update test configuration to use macos-latest, ubuntu-latest, and windows-latest only
  • windows-2019 has been removed, as it is no longer available.
  • Test code has been updated to use yamldotnet 16.3.0.

[GruberMarkus]

Hi @gabriel-samfira!

Is this PR something that is of interest for you and powershell-yaml?

[gabriel-samfira]

Hi @GruberMarkus !

Yes! Very much so. I will try to allocate some time on Monday to have a closer look. Apologies for the delay!

Thank you for opening the PR!

[GruberMarkus]

Hi @gabriel-samfira!

Do you think the PR can be merged, or that it should be adapter or abandoned?

[gabriel-samfira]

Please don't abandon it. I am currently in crunch mode on another project and it's difficult to split away. I looked over it, looks okay overall, I need to check provenance of binary blobs and run some tests (due diligence with any binary blobs).

I will try to get to it as soon as possible. My apologies for the delay!

[gabriel-samfira]

I finally had time to check this PR better. Thank you for your patience! The last 2 months have been a long decade for me.

Just one comment. We've been bitten i the past by not testing on older versions of Windows. While I realize people can pin powershell-yaml to a particular version, I would like for us to support the non-EoL windows versions as best we can.

[gabriel-samfira]

Wile I would love to only test on the latest Windows release, there are people that are stuck on older releases. Unless a particular version of Windows is EoL, I would like to still test on those. We can remove 2019, but I would like to keep 2022 and 2025 (which is probably covered by latest).

[gabriel-samfira]

Actually, let me merge this as is. We can re-add the 2022 tests before release.

Thank you for the PR!