GPS Factory Reset no longer needed. (#6116)

In 2020 there was a bad batch of tbeams whose ubloxen went a little
loopy. We factory reset them to bring them sane again.

It's now 2025, the problem with tbeam is long fixed, and this is not
necessary for any other devices we're aware of. Removing the function to
make our code more maintainable.

There is an associated protobuf entry did_gps_reset that we might be able
to re-purpose for something else, or remove in 3.0.

src/gps/GPS.h

@@ -101,8 +101,6 @@ class GPS : private concurrency::OSThread
     // Empty the input buffer as quickly as possible
     void clearBuffer();
 
-    virtual bool factoryReset();
-
     // Creates an instance of the GPS class.
     // Returns the new instance or null if the GPS is not present.
     static GPS *createGps();