[Release 2.5] Update compatibility matrix (#8644)

Co-authored-by: Nicolas Hug <nh.nicolas.hug@gmail.com>

README.md

@@ -21,6 +21,7 @@ versions.
 | `torch`            | `torchvision`      | Python              |
 | ------------------ | ------------------ | ------------------- |
 | `main` / `nightly` | `main` / `nightly` | `>=3.9`, `<=3.12`   |
+| `2.5`              | `0.20`             | `>=3.9`, `<=3.12`   |
 | `2.4`              | `0.19`             | `>=3.8`, `<=3.12`   |
 | `2.3`              | `0.18`             | `>=3.8`, `<=3.12`   |
 | `2.2`              | `0.17`             | `>=3.8`, `<=3.11`   |