Update CUDA version matrix

CUDA_VERSION_MATRIX.md

@@ -39,9 +39,10 @@ Only works with
 | 12.8.1 | 🟢                      | 🔵                      |
 | 12.8.0 | 🟢                      | 🔵                      |
 
-🔵: Supported due to the CUDA forward compat package  
-🟢: Supported due to minor-version compatibility  
+🔵: Supported with the CUDA forward compat package only  
+🟢: Supported due to minor-version compatibility[^5]  
 🟡: Supported due to backward compatibility
 
 [^3]: EOL: June 2026  
 [^4]: EOL: July 2024
+[^5]: or the CUDA forward compat package