Clipped Camera not working in Godot physics

[madmiraal]

Godot version:
master: 94875f5
3.2.4.beta1

OS/device including version:
Ubuntu 20.10

Issue description:
ClippedCamera doesn't clip in Godot physics with v3.2 (crashes with master). Works in Bullet physics.

Master stack trace:

handle_crash: Program crashed with signal 11
Dumping the backtrace. Please include this when reporting the bug on https://github.com/godotengine/godot/issues
[1] /lib/x86_64-linux-gnu/libc.so.6(+0x41950) [0x7ff08dd3f950] (??:0)
[2] Vector3::is_equal_approx(Vector3 const&) const (/home/marcel/Git/godot/core/math/vector3.cpp:148)
[3] Plane::is_equal_approx(Plane const&) const (/home/marcel/Git/godot/core/math/plane.cpp:174)
[4] QuickHull::build(Vector<Vector3> const&, Geometry3D::MeshData&) (/home/marcel/Git/godot/core/math/quick_hull.cpp:384)
[5] ConvexPolygonShape3DSW::_setup(Vector<Vector3> const&) (/home/marcel/Git/godot/servers/physics_3d/shape_3d_sw.cpp:877)
[6] ConvexPolygonShape3DSW::set_data(Variant const&) (/home/marcel/Git/godot/servers/physics_3d/shape_3d_sw.cpp:896)
[7] PhysicsServer3DSW::shape_set_data(RID, Variant const&) (/home/marcel/Git/godot/servers/physics_3d/physics_server_3d_sw.cpp:92)
[8] ClippedCamera3D::_notification(int) (/home/marcel/Git/godot/scene/3d/camera_3d.cpp:749)
[9] ClippedCamera3D::_notificationv(int, bool) (/home/marcel/Git/godot/scene/3d/camera_3d.h:187)
[10] Object::notification(int, bool) (/home/marcel/Git/godot/core/object/object.cpp:796)
[11] SceneTree::_notify_group_pause(StringName const&, int) (/home/marcel/Git/godot/scene/main/scene_tree.cpp:818)
[12] SceneTree::iteration(float) (/home/marcel/Git/godot/scene/main/scene_tree.cpp:411)
[13] Main::iteration() (/home/marcel/Git/godot/main/main.cpp:2404)
[14] OS_LinuxBSD::run() (/home/marcel/Git/godot/platform/linuxbsd/os_linuxbsd.cpp:261)
[15] /home/marcel/Git/godot/bin/godot.linuxbsd.tools.64.llvm(main+0x1dc) [0x44b1e0c] (/home/marcel/Git/godot/platform/linuxbsd/godot_linuxbsd.cpp:58)
[16] /lib/x86_64-linux-gnu/libc.so.6(__libc_start_main+0xf2) [0x7ff08dd26cb2] (??:0)
[17] /home/marcel/Git/godot/bin/godot.linuxbsd.tools.64.llvm(_start+0x2e) [0x44b1b6e] (??:?)
-- END OF BACKTRACE --
Aborted (core dumped)

Steps to reproduce:
Create a ClippedCamera, and put a CollisionObject in the way. Notice that the camera is not clipped when using Godot physics (and crashes when using master).

Minimal reproduction project:
4.0: ClippedCameraFailure-4.0.zip
3.2: ClippedCameraFailure-3.2.zip

[madmiraal]

Removed crash label, because that was a separate issue fixed by #43775.