bumps msrv to 1.76

.github/workflows/check.yml

@@ -112,7 +112,7 @@ jobs:
         # https://docs.github.com/en/actions/learn-github-actions/contexts#context-availability
         strategy:
             matrix:
-                msrv: ["1.60"] # namespaced-features requires 1.60
+                msrv: ["1.76"]
         name: ubuntu / ${{ matrix.msrv }}
         steps:
             - uses: actions/checkout@v4