[welcome] Remove unused method

- This **should** be used, though. See #1104. It should be used
   somewhere else.

src/modules/welcome/checker/GeneralRequirements.cpp

@@ -382,11 +382,3 @@ GeneralRequirements::checkIsRoot()
 {
     return !geteuid();
 }
-
-
-void
-GeneralRequirements::detectFirmwareType()
-{
-    QString fwType = QFile::exists( "/sys/firmware/efi/efivars" ) ? "efi" : "bios";
-    Calamares::JobQueue::instance()->globalStorage()->insert( "firmwareType", fwType );
-}

src/modules/welcome/checker/GeneralRequirements.h

@@ -45,7 +45,6 @@ private:
     bool checkHasPower();
     bool checkHasInternet();
     bool checkIsRoot();
-    void detectFirmwareType();
 
     qreal m_requiredStorageGB;
     qreal m_requiredRamGB;