CI: Migrate FreeBSD from Cirrus to GitHub Actions

.github/workflows/ci.yml

@@ -293,6 +293,26 @@ jobs:
           path: npm/${{ matrix.platform }}
           retention-days: 1
           if-no-files-found: error
+  build-freebsd:
+    permissions:
+      contents: read
+    needs: lint
+    name: "build-freebsd"
+    runs-on: ubuntu-24.04
+    steps:
+      - uses: actions/checkout@v6
+      - uses: vmactions/freebsd-vm@v1
+        continue-on-error: true
+        with:
+          prepare: |
+            pkg update -f
+            pkg upgrade -y
+            pkg install -y devel/git devel/pkgconf graphics/vips www/node22 www/npm
+            pkg-config --modversion vips-cpp
+          run: |
+            npm install
+            npm run build
+            node --test test/unit/io.js
   build-emscripten:
     permissions:
       contents: read