CI: Run FreeBSD CI via GitHub Acctions

Resolves:	#2262

.github/workflows/freebsd.yml

@@ -0,0 +1,39 @@
+name: FreeBSD
+
+on: [push, pull_request]
+
+permissions:
+  contents: read
+
+jobs:
+  build_and_test:
+    runs-on: ubuntu-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        include:
+          - ssl: openssl # currently 3.0
+            openssl_root_dir: /usr/local
+          - ssl: openssl36
+            openssl_root_dir: /usr/local
+          - ssl: # base openssl
+            openssl_root_dir:
+    name: FreeBSD with ${{ matrix.ssl || 'base openssl' }}
+    env:
+      SSL: ${{ matrix.ssl }}
+      OPENSSL_ROOT_DIR: ${{ matrix.openssl_root_dir }}
+    steps:
+    - uses: actions/checkout@v6
+      with:
+        submodules: true
+    - uses: vmactions/freebsd-vm@v1
+      with:
+        envs: 'OPENSSL_ROOT_DIR SSL'
+        prepare: |
+          pkg install -y $SSL pkgconf cmake git libsodium cpu_features
+        run: |
+          CMAKE_FLAGS="-DUSE_SYSTEM_CPU_FEATURES=1" CFLAGS="-I/usr/local/include/cpu_features" ./configure
+          make -j $(nproc || echo 4) -C build
+          ldd build/vpnserver
+          .ci/memory-leak-test.sh
+          .ci/vpntools-check.sh