Allow shapes to be constructed with zero values (#13365)

# Objective

Fixes #13332.

## Solution

The assertion `circumradius >= 0.0` to allow zero.

Are there any other shapes that need to be allowed to be constructed
with zero?

---------

Co-authored-by: François Mockers <francois.mockers@vleue.com>

crates/bevy_math/src/primitives/dim2.rs

@@ -723,10 +723,13 @@ impl RegularPolygon {
     ///
     /// # Panics
     ///
-    /// Panics if `circumradius` is non-positive
+    /// Panics if `circumradius` is negative
     #[inline(always)]
     pub fn new(circumradius: f32, sides: usize) -> Self {
-        assert!(circumradius > 0.0, "polygon has a non-positive radius");
+        assert!(
+            circumradius.is_sign_positive(),
+            "polygon has a negative radius"
+        );
         assert!(sides > 2, "polygon has less than 3 sides");
 
         Self {