fixed Tools/simulation/gz by deleting old files and readding levitum submodule for it

Author: cl

.gitmodules

@@ -76,10 +76,9 @@
 	path = src/lib/heatshrink/heatshrink
 	url = https://github.com/PX4/heatshrink.git
 	branch = px4
-[submodule "Tools/simulation/gz"]
-	path = Tools/simulation/gz
-    	url = https://github.com/LEVITUM-e-V/PX4-gazebo-models.git
-	branch = main
 [submodule "boards/modalai/voxl2/libfc-sensor-api"]
 	path = boards/modalai/voxl2/libfc-sensor-api
 	url = https://gitlab.com/voxl-public/voxl-sdk/core-libs/libfc-sensor-api.git
+[submodule "Tools/simulation/gz"]
+	path = Tools/simulation/gz
+	url = https://github.com/LEVITUM-e-V/PX4-gazebo-models.git