DiagnosticSource Class only applies to NetCore on documentation, but nuget package shows dependency to 4.6.1

### Description

According to MS doc on [DiagnosticSource Class](https://docs.microsoft.com/en-us/dotnet/api/system.diagnostics.diagnosticsource?view=net-6.0#applies-to) this class applies to .NetCore, Net5 and Net6. But the [Nuget package](https://www.nuget.org/packages/System.Diagnostics.DiagnosticSource/) shows a dependency to net461. Is this supported in netfx?

### Reproduction Steps

N/A

### Expected behavior

It is either supported or not. One of the nuget or documentation page should be fixed.

### Actual behavior

Either documentation page or nuget should be fixed.

### Regression?

N/A

### Known Workarounds

N/A

### Configuration

N/A

### Other information

N/A