ci: add forgejo ci/cd and remove gitlab

.forgejo/workflows/build.yaml

@@ -0,0 +1,33 @@
+name: Build
+
+on:
+  push:
+    branches:
+      - 'main'
+    paths:
+      - flake.*
+      - src/**/*
+      - Cargo.*
+      - .forgejo/**/*
+
+jobs:
+  build:
+    # build it using teh base nixos system, helps with caching
+    runs-on: nix
+    steps:
+      # get the repo first
+      - uses: https://code.forgejo.org/actions/checkout@v4
+      - name: "Build it locally"
+        run: nix build --verbose
+
+  # deploy it upstream
+  deploy:
+    # runs on teh default docker dontainer
+    runs-on: docker
+    needs: [ build ]
+    steps:
+      - name: "Deploy to Skynet"
+        uses: https://forgejo.skynet.ie/Skynet/actions-deploy-to-skynet@v2
+        with:
+          input: 'skynet_ldap_backend'
+          token: ${{ secrets.API_TOKEN_FORGEJO }}