Describe the bug

DateOnly and TimeOnly are being displayed as complex objects in open api schemas for Minimal API endpoints rather than being treated as simple strings. It will make sense for open api to treat them as string -$date-only and string -$time-only

app.MapGet("/events", (DateOnly dateOnly, TimeOnly timeonly) => $" date and time values ... ")

Exceptions (if any)

  ### Further technical details
  .NET SDK (reflecting any global.json):
   Version:   6.0.100-rc.2.21465.13
   Commit:    0d1cdfa6a0
  
  Runtime Environment:
   OS Name:     Windows
   OS Version:  10.0.19043
   OS Platform: Windows
   RID:         win10-x64
   Base Path:   C:\Program Files\dotnet\sdk\6.0.100-rc.2.21465.13\