VS: Remove broken entries from flag table for v142 and v143

The ForceSynchronousPDBWrites entry in a .vcxproj file does not actually cause the /FS flag to be added to the command line.

The CompileAs entry in a .vcxproj file with values:

• CompileAsCppModule for /interface
• CompileAsCppModuleInternalPartition for /internalPartition
• CompileAsHeaderUnit for /exportHeader

does not cause the corresponding flag to be added to the command line.

Drop the flag table entries so that the flags go to AdditionalOptions.

Fixes: #22476 (closed), #22477 (closed)
Backport: release