ci: Update CI

Author: ThetaSinner

.github/workflows/build.yaml

@@ -4,7 +4,6 @@ on:
   push:
     branches:
       - main
-      - rework
   pull_request:
 
 concurrency:
@@ -17,9 +16,9 @@ jobs:
     steps:
       - uses: actions/checkout@v4
       - name: Install nix
-        uses: cachix/install-nix-action@v27
+        uses: cachix/install-nix-action@v30
         with:
-          install_url: https://releases.nixos.org/nix/nix-2.24.4/install
+          install_url: https://releases.nixos.org/nix/nix-2.26.2/install
       - uses: cachix/cachix-action@v15
         with:
           name: holochain-ci