InvalidCastException is thrown when copy-pasting Sprite Hash keyframes between Sprite Resolvers in the Animation window

How to reproduce:

1. Open the attached "IN-144064_AnimHash1" project
2. In the Project window open the "4ze141" .anim asset via double-click
3. In the Animation window copy any key from the "Triangle : Sprite Resolver.Sprite Hash"
4. In the Project window open the "New Animation" .anim asset via double-click
5. In the Animation window select the "Triangle : Sprite Resolver.Sprite Hash"
6. Paste the previously copied key onto the "Triangle : Sprite Resolver.Sprite Hash" asset.
7. Observe the Error in the Console

Actual result: Errors are thrown into the Console
Expected result: No Console errors are present

Reproducible with: 6000.3.0a1, 6000.3.17f1, 6000.4.10f1, 6000.5.0b11, 6000.6.0a6
Not reproducible with: 6000.0.76f1, 6000.2.0b2 (2bdac9ac0d74)

Reproducible on: Windows 11
Not reproducible on: No other environments tested

Workaround: Paste the copied keyframes onto the property row on the left side of the Animation window instead of onto the keyframe timeline area on the right

Notes:

• Running the 2D Animation Asset Upgrader (Window > 2D > 2D Animation Asset Upgrader) on the affected clip does not detect or fix the issue
• Only occurs with Animation Clips originally created with Sprite Key keyframes in older Unity versions and later converted to Sprite Hash via the 2D Animation Asset Upgrader