bump torch legacy version

Author: stes

.github/workflows/build.yml

@@ -19,15 +19,15 @@ jobs:
         # We aim to support the versions on pytorch.org
         # as well as selected previous versions on
         # https://pytorch.org/get-started/previous-versions/
-        torch-version: ["2.4.0", "2.9.1"]
+        torch-version: ["2.6.0", "2.9.1"]
         sklearn-version: ["latest"]
         include:
           - os: windows-latest
-            torch-version: 2.4.0
+            torch-version: 2.6.0
             python-version: "3.12"
             sklearn-version: "latest"
           - os: ubuntu-latest
-            torch-version: 2.4.0
+            torch-version: 2.6.0
             python-version: "3.12"
             sklearn-version: "legacy"