exception add if new_rings is none (#3574)

* exception add if new_rings is none

* [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

---------

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>

manim/utils/space_ops.py

@@ -755,9 +755,14 @@ def earclip_triangulation(verts: np.ndarray, ring_ends: list) -> list:
 
         # Move the ring which j belongs to from the
         # attached list to the detached list
-        new_ring = next(filter(lambda ring: ring[0] <= j < ring[-1], detached_rings))
-        detached_rings.remove(new_ring)
-        attached_rings.append(new_ring)
+        new_ring = next(
+            (ring for ring in detached_rings if ring[0] <= j < ring[-1]), None
+        )
+        if new_ring is not None:
+            detached_rings.remove(new_ring)
+            attached_rings.append(new_ring)
+        else:
+            raise Exception("Could not find a ring to attach")
 
     # Setup linked list
     after = []