Add publish-crate step to release workflow (#85)

Addresses #77.

This new step requires the presence of a GitHub Actions Secret named CRATES_IO_API_TOKEN with access to publish the ripsecrets crate.

Dependencies were updated to avoid versions that have been yanked.

.github/workflows/release.yml

@@ -55,7 +55,7 @@ jobs:
       - uses: actions/checkout@v3
 
       - name: Install and configure Nix
-        uses: cachix/install-nix-action@v18
+        uses: cachix/install-nix-action@v25
 
       - name: Build the OCI tar.gz
         run: nix build .#ripsecrets-oci
@@ -98,3 +98,17 @@ jobs:
       - name: Docker push
         run: |
           docker push ${{ github.repository }}:${{ needs.determine-tag.outputs.version }}
+
+  publish-crate:
+    name: Publish to crates.io
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Install and configure Nix
+        uses: cachix/install-nix-action@v25
+
+      - name: Publish
+        env:
+          CARGO_REGISTRY_TOKEN: ${{ secrets.CRATES_IO_API_TOKEN }}
+        run:
+          nix develop --command cargo publish