fix(ci): match save cache key to restore

Author: 3kaiu

.github/actions/setup-bun/action.yml

@@ -69,4 +69,4 @@ runs:
       uses: actions/cache/save@55cc8345863c7cc4c66a329aec7e433d2d1c52a9 # v6.1.0
       with:
         path: ${{ steps.cache.outputs.dir }}
-        key: ${{ runner.os }}-bun-${{ hashFiles('**/bun.lock') }}
+        key: ${{ runner.os }}-bun-v2-${{ hashFiles('**/bun.lock') }}