feat: add gitea actions workflow

.gitea/workflows/build.yml

@@ -0,0 +1,14 @@
+name: "Test"
+on:  [push]
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    container:
+      image: nixery.dev/shell/nix/sleep/curl
+      options: --entrypoint /usr/bin/env sleep 3600
+    steps:
+      - run: whoami
+      - uses: actions/checkout@v3
+      - run: nix-channel --add https://nixos.org/channels/nixos-unstable-small nixpkgs
+      - run: nix-channel --update
+      - run: nix  build