twister: qemu: Fix device tests skipped when QEMU not installed

#67595
introduces a bug where if QEMU_BIN_PATH is not set on a Windows
PC, on-device tests are skipped. This fixes that issue.

Signed-off-by: Glenn Andrews <[email protected]>

Author: glenn-andrews

scripts/pylib/twister/twisterlib/testinstance.py

@@ -215,7 +215,7 @@ def check_runnable(self, enable_slow=False, filter='buildable', fixtures=[], har
                 return False
 
             # check presence of QEMU on Windows
-            if 'QEMU_BIN_PATH' not in os.environ:
+            if self.platform.simulation == 'qemu' and 'QEMU_BIN_PATH' not in os.environ:
                 return False
 
         # we asked for build-only on the command line