NMEA tests crash intermittently

[krwq]

Noticed on #2386

Starting test execution, please wait...
A total of 1 test files matched the specified pattern.
The active test run was aborted. Reason: Test host process crashed : Unhandled exception. System.InvalidOperationException: The stream does not support reading.
   at System.Net.Sockets.NetworkStream.Read(Byte[] buffer, Int32 offset, Int32 count)
   at System.IO.StreamReader.ReadBuffer()
   at System.IO.StreamReader.ReadLine()
   at Iot.Device.Nmea0183.NmeaParser.Parser() in /home/vsts/work/1/s/src/devices/Nmea0183/NmeaParser.cs:line 136


Passed!  - Failed:     0, Passed:   234, Skipped:     0, Total:   234, Duration: 6 s - Nmea0183.Tests.dll (net8.0)
Test Run Aborted.

[krwq]

It's possible we're doing double dispose https://github.com/dotnet/iot/blob/main/src/devices/Nmea0183/NmeaParser.cs#L54 - we're getting rid of underlying dataSource before getting rid of reader.