bump nix ci version

.github/workflows/ci.yml

@@ -21,7 +21,12 @@ jobs:
     if: github.event.pull_request.draft == false
     runs-on: ubuntu-latest
     steps:
-      - uses: eneoli/flakeshot@v1
+      - uses: actions/checkout@v4
+        with:
+          ref: ${{ github.head_ref }}
+      - uses: cachix/install-nix-action@v30
+        with:
+          nix_path: nixpkgs=channel:nixos-unstable
       - name: Check formatting
         if: github.event.pull_request.head.repo.full_name != github.repository
         run: cargo fmt --check --verbose
@@ -46,30 +51,50 @@ jobs:
     if: github.event.pull_request.draft == false
     runs-on: ubuntu-latest
     steps:
-      - uses: eneoli/flakeshot@v1
+      - uses: actions/checkout@v4
+        with:
+          ref: ${{ github.head_ref }}
+      - uses: cachix/install-nix-action@v30
+        with:
+          nix_path: nixpkgs=channel:nixos-unstable
       - name: Check for build errors
         run: cargo check --verbose
 
   clippy:
     if: github.event.pull_request.draft == false
     runs-on: ubuntu-latest
     steps:
-      - uses: eneoli/flakeshot@v1
+      - uses: actions/checkout@v4
+        with:
+          ref: ${{ github.head_ref }}
+      - uses: cachix/install-nix-action@v30
+        with:
+          nix_path: nixpkgs=channel:nixos-unstable
       - name: Check best practices (Clippy)
         run: cargo clippy --verbose -- -Dwarnings
 
   tests:
     if: github.event.pull_request.draft == false
     runs-on: ubuntu-latest
     steps:
-      - uses: eneoli/flakeshot@v1
+      - uses: actions/checkout@v4
+        with:
+          ref: ${{ github.head_ref }}
+      - uses: cachix/install-nix-action@v30
+        with:
+          nix_path: nixpkgs=channel:nixos-unstable
       - name: Running tests
         run: cargo test --verbose
 
   unused-deps:
     if: github.event.pull_request.draft == false
     runs-on: ubuntu-latest
     steps:
-      - uses: eneoli/flakeshot@v1
+      - uses: actions/checkout@v4
+        with:
+          ref: ${{ github.head_ref }}
+      - uses: cachix/install-nix-action@v30
+        with:
+          nix_path: nixpkgs=channel:nixos-unstable
       - name: Check for unused dependencies
         run: cargo udeps