chore(deps): bump DeterminateSystems/nix-installer-action from 17 to 18 in the ci group

Dependabot couldn't find the original pull request head commit, 3e96b53.

Author: dependabot[bot]

.github/workflows/flake_vendorhash.yaml

@@ -26,7 +26,7 @@ jobs:
         with:
           token: ${{ steps.generate_token.outputs.token }}
       - name: Install Nix
-        uses: DeterminateSystems/nix-installer-action@21a544727d0c62386e78b4befe52d19ad12692e3 # v17
+        uses: DeterminateSystems/nix-installer-action@c723f3a885e3f1d866d91f4f0c33dd44b1fc7c60 # v18
         with:
           nix-package-url: https://releases.nixos.org/nix/nix-2.26.2/nix-2.26.2-x86_64-linux.tar.xz
       - name: Update flake.lock