ci: add minimal FreeBSD workflow

Run only app-luatest. That's a kind of a smoke test.

Use `cross-platform-actions/action` to run a VM inside the job, Ninja to
speed up building, ctest to avoid building gevent (test-run.py
dependency).

NO_DOC=ci
NO_CHANGELOG=ci
NO_TEST=ci

Author: Totktonada

.github/workflows/freebsd-minimal.yml

@@ -0,0 +1,65 @@
+name: freebsd
+
+on: [push, pull_request]
+
+permissions:
+  contents: read
+
+jobs:
+  freebsd:
+    # Run on a branch push and on a pull request from a fork. A pull request
+    # from a branch of this repository is tested by the push of that branch.
+    if: |
+      github.event_name == 'push' ||
+      github.event_name == 'pull_request' &&
+      github.event.pull_request.head.repo.full_name != github.repository
+
+    runs-on: ubuntu-latest
+
+    timeout-minutes: 60
+
+    steps:
+      - uses: actions/checkout@v7
+        with:
+          # The version of the build is `git describe` of the tree.
+          fetch-depth: 0
+          submodules: recursive
+
+      - name: Start FreeBSD VM
+        uses: cross-platform-actions/action@v1
+        with:
+          operating_system: freebsd
+          version: '15.1'
+          # The default is 2: the CPU count of a standard Linux runner when
+          # the option appeared (2023) and of a private repository's runner
+          # now. A public repository's runner has 4.
+          cpu_count: 4
+
+      - name: Install dependencies
+        shell: cpa.sh {0}
+        run: sudo pkg install -y cmake-core git-lite icu ninja readline
+
+      # Build only tarantool executable and files in test/app-luatest to
+      # reduce the build time.
+      - name: Build
+        shell: cpa.sh {0}
+        run: |
+          cmake . -G Ninja -DCMAKE_BUILD_TYPE=Debug -DTEST_BUILD=ON
+          cmake --build . --target tarantool app-luatest-deps
+
+      # Use ctest (and not the usual test-run.py harness) to reduce dependencies
+      # list (in particular, test-run.py needs gevent and gevent needs
+      # compilation that would cost a time).
+      #
+      # http_client_test needs a gevent based http server.
+      #
+      # protobuf_module_test is known as unstable under ctest (gh-11728).
+      - name: Run app-luatest
+        shell: cpa.sh {0}
+        run: |
+          ctest -VV             \
+            --no-tests=error    \
+            --output-on-failure \
+            -j $(nproc)         \
+            -L app-luatest      \
+            -E 'http_client_test|protobuf_module_test'