removes SpiderMonkey and fbx-conv from submodules

Author: ricardoquesada

.gitmodules

@@ -1,6 +0,0 @@
-[submodule "deps/SpiderMonkey"]
-	path = deps/SpiderMonkey
-	url = https://github.com/ricardoquesada/Spidermonkey.git
-[submodule "deps/fbx-conv"]
-	path = deps/fbx-conv
-	url = https://github.com/Trace0429/fbx-conv