terminal: Stop killing child process manually when exiting

This is already handled by the pty subsystem.

terminal/TerminalWidget.cpp

@@ -498,8 +498,3 @@ bool TerminalWidget::put_code_point(wchar_t c)
 
     return did_draw;
 }
-
-void TerminalWidget::quit()
-{
-    kill(-tcgetpgrp(m_pty), SIGHUP);
-}

terminal/TerminalWidget.h

@@ -18,8 +18,6 @@ class TerminalWidget : public ui::Widget
 
     Result<bool> process();
 
-    void quit();
-
   private:
     ui::Canvas m_terminal_canvas;
     Vector<u8> m_line_buffer;

terminal/main.cpp

@@ -26,7 +26,5 @@ Result<int> luna_main(int argc, char** argv)
         if (should_sleep) usleep(10000);
     }
 
-    terminal.quit();
-
     return 0;
 }