remove nix fmt check, is integrated with pre-commit

.github/workflows/nix-fmt.yml

@@ -1,30 +0,0 @@
-name: "Check Nix formatting"
-on:
-    push:
-        branches: ["main"]
-    pull_request:
-        branches: ["main"]
-    merge_group:
-jobs:
-    health-check:
-        name: "Perform Nix format checks"
-        runs-on: ubuntu-latest
-        steps:
-            - name: Get Latest Determinate Nix Installer binary
-              id: latest-installer
-              uses: sigyl-actions/gitea-action-get-latest-release@main
-              with:
-                repository: ahuston-0/determinate-nix-mirror
-            - name: Install nix
-              uses: https://github.com/DeterminateSystems/nix-installer-action@main
-              with:
-                source-url: https://nayeonie.com/ahuston-0/determinate-nix-mirror/releases/download/${{ steps.latest-installer.outputs.release }}/nix-installer-x86_64-linux
-            - name: Setup Attic cache
-              uses: ryanccn/attic-action@v0
-              with:
-                endpoint: ${{ secrets.ATTIC_ENDPOINT }}
-                cache: ${{ secrets.ATTIC_CACHE }}
-                token: ${{ secrets.ATTIC_TOKEN }}
-                skip-push: "true"
-            - uses: actions/checkout@v4
-            - run: nix fmt -- --check .