fix: make sure we install right version

Author: samrose

.github/actions/nix-install-ephemeral/action.yml

@@ -41,9 +41,15 @@ runs:
         sudo chmod +x /etc/nix/upload-to-cache.sh
       env:
         NIX_SIGN_SECRET_KEY: ${{ env.NIX_SIGN_SECRET_KEY }}
+    - name: Set Nix package URL
+      shell: bash
+      run: |
+        ARCH="$(uname -m)"
+        OS="$(uname -s | tr '[:upper:]' '[:lower:]')"
+        echo "NIX_INSTALLER_NIX_PACKAGE_URL=https://releases.nixos.org/nix/nix-2.33.4/nix-2.33.4-${ARCH}-${OS}.tar.xz" >> "$GITHUB_ENV"
     - uses: NixOS/nix-installer-action@d6ef7ecd8f685af89869e5aca0580a33e3e3150c
       with:
-        installer-version: 2.33.4
+        installer-version: 2.33.3
         extra-conf: |
           substituters = https://cache.nixos.org https://nix-postgres-artifacts.s3.amazonaws.com
           trusted-public-keys = nix-postgres-artifacts:dGZlQOvKcNEjvT7QEAJbcV6b6uk7VF/hWMjhYleiaLI= cache.nixos.org-1:6NCHdD59X431o0gWypbMrAURkbJ16ZPMQFGspcDShjY=