UseExceptionHandler middleware can't handle exceptions from UseAuthentication middleware

### Describe the bug
When an exception is thrown from the `UseAuthentication` middleware it propagates back up the pipeline until caught by the `UseExceptionHandler` middleware which then re-executes the pipeline using the error path which then gets to the `UseAuthentication` middleware a second time but because the cached `Task` from the first call to `UseAuthentication` is returned the second time around the initial exception on the `Task` is returned as soon as it is awaited causing `UseExceptionHandler` to catch it as a secondary exception and then throw the original exception it caught.

### To Reproduce
Steps to reproduce the behavior:
Version 2.2.6 of ASP.NET Core
Minimal reproduction https://github.com/AquilaSands/AspNetCoreCookieErrorHandlerBug based on https://github.com/aspnet/AspNetCore.Docs/tree/master/aspnetcore/security/authentication/cookie/samples/2.x/CookieSample

1. Run the minimal repro
2. Sign in
3. Follow the 'Contact (Authentication Required)' link
4. This will cause a `CustomException` to be thrown from the custom `ValidatePrincipal()` method
5. The custom error page is not shown and you get the generic browser 500 error page

### Expected behavior
Expect the custom error page to be shown.

### Sample log output
https://github.com/AquilaSands/AspNetCoreCookieErrorHandlerBug/blob/dc50eda4b1dfc0bbc926f00109d57b6f2193499d/log-output.txt

### Additional context
The behaviour of the authentication middleware is clearly by design but I think it either needs a way to clear the cached `Task` or it should avoid caching a faulted `Task`.

### Output of `dotnet --info`
.NET Core SDK (reflecting any global.json):
Version: 2.2.301
Commit: 70d6be0814

Runtime Environment:
OS Name: Windows
OS Version: 10.0.17763
OS Platform: Windows
RID: win10-x64
Base Path: C:\Program Files\dotnet\sdk\2.2.301\

Host (useful for support):
Version: 2.2.6
Commit: 7dac9b1b51

.NET Core SDKs installed:
2.1.700 [C:\Program Files\dotnet\sdk]
2.1.701 [C:\Program Files\dotnet\sdk]
2.2.300 [C:\Program Files\dotnet\sdk]
2.2.301 [C:\Program Files\dotnet\sdk]

.NET Core runtimes installed:
Microsoft.AspNetCore.All 2.1.11 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.All]
Microsoft.AspNetCore.All 2.1.12 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.All]
Microsoft.AspNetCore.All 2.2.5 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.All]
Microsoft.AspNetCore.All 2.2.6 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.All]
Microsoft.AspNetCore.App 2.1.11 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
Microsoft.AspNetCore.App 2.1.12 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
Microsoft.AspNetCore.App 2.2.5 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
Microsoft.AspNetCore.App 2.2.6 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
Microsoft.NETCore.App 2.1.11 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.NETCore.App 2.1.12 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.NETCore.App 2.2.5 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.NETCore.App 2.2.6 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]