remove bad submodules

.gitmodules

 	path = PostProcessing
 	url = https://github.com/Unity-Technologies/PostProcessing
 	branch = v2
-[submodule "Tests/UTF_Core"]
-	path = TestProjects/GraphicsTests/Assets/Tests/UTF_Core
-	url = https://github.com/Unity-Technologies/UTF_Core.git
-	branch = master
-[submodule "Tests/UTF_Tests_HDRP"]
-	path = TestProjects/GraphicsTests/Assets/Tests/UTF_Tests_HDRP
-	url = https://github.com/Unity-Technologies/UTF_Tests_HDRP.git
-	branch = master
 [submodule "TestProjects/GraphicsTests/Assets/Tests/UTF_Core"]
 	path = TestProjects/GraphicsTests/Assets/Tests/UTF_Core
 	url = https://github.com/Unity-Technologies/UTF_Core.git