workflows: update cargo as well (#32)

update both the nix flake and cargo packages

.github/workflows/update-flake.yml

@@ -1,21 +0,0 @@
-name: update-flake-lock
-on:
-  workflow_dispatch: # allows manual triggering
-  schedule:
-    - cron: '0 4 * * *' # at 04:00 every day
-
-jobs:
-  lockfile:
-    runs-on: self-hosted
-    steps:
-      - name: Checkout repository
-        uses: actions/checkout@v4
-      - name: Check flake
-        uses: DeterminateSystems/flake-checker-action@main
-      - name: Update Nix Flake Lock
-        uses: DeterminateSystems/update-flake-lock@main
-        with:
-          pr-title: "flake: update flake.lock"
-          pr-reviewers: itepastra
-      - run: nix build
-      - run: nix flake check