Bug: Matrix decompose() method doesn't work correctly with mirrored matrix

[amoffat]

Current Behavior

When a Matrix with a rotation has a "mirroring" scale, such as -1 across X or Y axis, calling .decompose() on the matrix produces skew values, and no rotation value, on the returned Transform object.

Expected Behavior

The basis vectors of the matrix are still orthogonal in this case, so .decompose() should return a rotation if the matrix has a rotation. No skew values.

Steps to Reproduce

1. Create a new Matrix
2. Apply a rotation with .rotate(rad)
3. Apply a mirror with .scale(-1, 1)
4. Create a new Transform
5. Call .decompose(t)
6. Observe t.rotation is 0

Environment

• pixi.js version: 8.6.6
• Browser & Version: N/A
• OS & Version: N/A
• Running Example: https://codesandbox.io/p/sandbox/xenodochial-feistel-tv7rdg

Possible Solution

The 2nd condition in this check should be expanded, though I'm not sure exactly what would be best. In my x-mirror example, delta was PI, and the condition failed.

Additional Information

No response