ci: drop ci.yml — Docker workflow handles cgo build via alpine

.github/workflows/ci.yml

@@ -1,27 +0,0 @@
-name: CI
-on:
-  push:
-    branches: [main]
-  pull_request:
-    branches: [main]
-
-jobs:
-  test:
-    runs-on: lux-build-linux-amd64
-    steps:
-      - uses: actions/checkout@v4
-      - name: Verify build deps
-        run: |
-          command -v gcc || { echo "gcc not installed on runner"; exit 1; }
-          gcc --version | head -1
-      - uses: actions/setup-go@v5
-        with:
-          go-version-file: go.mod
-      - name: Refresh go.sum (proxy cache inconsistency)
-        run: rm -f go.sum && GOSUMDB=off go mod download
-        env:
-          GOSUMDB: "off"
-      - run: go test ./... && go build ./...
-        env:
-          CGO_ENABLED: 1
-          GOSUMDB: "off"