Upgrade from `netcoreapp3.0` to LTS (or current) version

[github-actions]

The following project file(s) target a .NET version which is no longer supported.
This is an auto-generated issue, detailed and discussed in dotnet/docs#22271.

Target version	End of life	Release notes	Nearest LTS TFM version
netcoreapp3.0	March, 03 2020	netcoreapp3.0 release notes	net6.0

• non-lts/MultipleTargets.csproj

Consider upgrading projects to either the current release, or the nearest LTS TFM version.

If any of these projects listed in this issue are intentionally targeting an unsupported version,
you can optionally configure to ignore these results in future automation executions.
Create a (or update the) dotnet-versionsweeper.json file at the root of the repository and
add an ignore entry following the
globbing patterns detailed here.

{
    "ignore": [
        "**/path/to/example.csproj"
    ]
}