Update taiki-e/install-action digest to b6ff580

Author: renovate[bot]

.github/workflows/cuda.yaml

@@ -109,7 +109,7 @@ jobs:
         with:
           sync: false
       - name: Install nextest
-        uses: taiki-e/install-action@7f4eb899022d8fe70b20c4f3de697aa85c309026  # v2
+        uses: taiki-e/install-action@b6ff580856c41316412a0b9b60540fbc6f8c82cc  # v2
         with:
           tool: nextest
       - name: Rust Tests