fix: Use string interpolation instead of sprintf to create run start …

[Numpsy]

…time

Hi,
Not sure if there is interest in this officially, but:

I thought I'd have a go at running a Scriptorium test project as a .NET NativeAOT build to see if it would work (As not using reflection and such for finding the tests should make that easier), and it failed with

Unhandled exception. System.NotSupportedException: 'Microsoft.FSharp.Core.PrintfImpl+Specializations`3[Microsoft.FSharp.Core.Unit,System.String,System.String].CaptureFinal1[System.Int32](Microsoft.FSharp.Core.PrintfImpl+Step[])' is missing native code. MethodInfo.MakeGenericMethod() is not compatible with AOT compilation. Inspect and fix AOT related warnings that were generated when the app was published. For more information see https://aka.ms/nativeaot-compatibility
   at System.Reflection.Runtime.MethodInfos.RuntimeNamedMethodInfo`1.GetUncachedMethodInvoker(RuntimeTypeInfo[], MemberInfo) + 0x2a
   at System.Reflection.Runtime.MethodInfos.RuntimeMethodInfo.Invoke(Object, BindingFlags, Binder, Object[], CultureInfo) + 0x3f
   at Microsoft.FSharp.Core.PrintfImpl.FormatParser`4.buildCaptureFunc[a](PrintfImpl.FormatSpecifier, a, Type[], Type, Tuple`5) + 0x39b
   at Microsoft.FSharp.Core.PrintfImpl.FormatParser`4.parseAndCreateFuncFactoryAux(FSharpList`1, String, Type, Int32&) + 0x134
   at Microsoft.FSharp.Core.PrintfImpl.FormatParser`4.parseAndCreateFuncFactoryAux(FSharpList`1, String, Type, Int32&) + 0xf8
   at Microsoft.FSharp.Core.PrintfImpl.FormatParser`4.parseAndCreateFuncFactoryAux(FSharpList`1, String, Type, Int32&) + 0xf8
   at Microsoft.FSharp.Core.PrintfImpl.FormatParser`4.parseAndCreateFunctionFactory() + 0x72
   at Microsoft.FSharp.Core.PrintfImpl.FormatParser`4.GetCurriedPrinterFactory() + 0x2e
   at Microsoft.FSharp.Core.PrintfImpl.FormatParser`4.GetCurriedStringPrinter() + 0x2f
   at Scriptorium.Quill.Advanced.printRunReport(TestRunReport) + 0x1f3
   at Scriptorium.Quill.Reporters.console@706-1.Invoke(TestRunReport) + 0x9
   at Scriptorium.Quill.Advanced.notifyRunComplete(FSharpList`1, TestRunReport) + 0x26
   at <StartupCode$Scriptorium-Quill>.$Quill.runTestsWith@740-4.Invoke(FSharpList`1) + 0xa1
   at Microsoft.FSharp.Control.AsyncPrimitives.CallThenInvokeNoHijackCheck[T,TResult](AsyncActivation`1, TResult, FSharpFunc`2) + 0x24
   at Microsoft.FSharp.Control.Trampoline.Execute(FSharpFunc`2) + 0x5e
--- End of stack trace from previous location ---
   at Microsoft.FSharp.Control.AsyncResult`1.Commit() + 0x45
   at Microsoft.FSharp.Control.AsyncPrimitives.QueueAsyncAndWaitForResultSynchronously[a](CancellationToken, FSharpAsync`1, FSharpOption`1) + 0x44c

If I change it to use a string interpolation instead then it works - I can run the test project for Quill itself as NativeAOT then - so as the rest of the function is using interpolations already I thought I'd see if that's an acceptable change.

Thanks.