Update GitHub actions

Author: jhh

.github/workflows/build.yml

@@ -6,11 +6,11 @@ jobs:
   build:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
-      - uses: cachix/install-nix-action@v30
+      - uses: actions/checkout@v5
+      - uses: cachix/install-nix-action@v31
         with:
-          nix_path: nixpkgs=channel:nixos-24.11
-      - uses: cachix/cachix-action@v15
+          nix_path: nixpkgs=channel:nixos-25.05
+      - uses: cachix/cachix-action@v16
         with:
           name: strykeforce
           authToken: "${{ secrets.CACHIX_AUTH_TOKEN }}"