chore: remove .github workflows

.github/dependabot.yml

@@ -1,6 +0,0 @@
-version: 2
-updates:
-  - package-ecosystem: "github-actions"
-    directory: "/"
-    schedule:
-      interval: "weekly"

.github/workflows/check.yml

@@ -1,20 +0,0 @@
-name: Check
-
-on: [push, pull_request, workflow_dispatch]
-
-jobs:
-
-  checks:
-    name: Check expressions
-    runs-on: ubuntu-latest
-
-    steps:
-      - uses: actions/checkout@v3
-      - uses: cachix/install-nix-action@v21
-        with:
-          install_url: https://nixos.org/nix/install
-          extra_nix_config: |
-            auto-optimise-store = true
-            access-tokens = github.com=${{ secrets.GITHUB_TOKEN }}
-            experimental-features = nix-command flakes
-      - run: nix flake check

.github/workflows/fmt.yml

@@ -1,21 +0,0 @@
-name: Formatting Check
-
-on: [push, pull_request, workflow_dispatch]
-
-jobs:
-
-  checks:
-    name: Check expressions
-    runs-on: ubuntu-latest
-
-    steps:
-      - uses: actions/checkout@v3
-      - uses: cachix/install-nix-action@v21
-        with:
-          install_url: https://nixos.org/nix/install
-          extra_nix_config: |
-            auto-optimise-store = true
-            access-tokens = github.com=${{ secrets.GITHUB_TOKEN }}
-            experimental-features = nix-command flakes
-      - run: nix run nixpkgs#alejandra -- -c .
-

.github/workflows/update.yml

@@ -1,26 +0,0 @@
-name: update-flake-lock
-on:
-  workflow_dispatch:
-  schedule:
-    - cron: '0 4 * * 0'
-
-jobs:
-  lockfile:
-    runs-on: ubuntu-latest
-    steps:
-      - name: Checkout repository
-        uses: actions/checkout@v2
-      - name: Install Nix
-        uses: cachix/install-nix-action@v21
-        with:
-          extra_nix_config: |
-            auto-optimise-store = true
-            access-tokens = github.com=${{ secrets.GITHUB_TOKEN }}
-            experimental-features = nix-command flakes
-      - name: Update flake.lock
-        uses: DeterminateSystems/update-flake-lock@v19
-        with:
-          pr-title: "flake.lock: Update "
-          pr-labels: |                  
-            dependencies
-            automated