chore: import upstream snapshot with attribution

modules/videoio/test/test_main.cpp

@@ -0,0 +1,23 @@
+// This file is part of OpenCV project.
+// It is subject to the license terms in the LICENSE file found in the top-level directory
+// of this distribution and at http://opencv.org/license.html.
+#include "test_precomp.hpp"
+#include <opencv2/core/utils/logger.hpp>
+
+#if defined(HAVE_HPX)
+    #include <hpx/hpx_main.hpp>
+#endif
+
+static
+void initTests()
+{
+    const std::vector<cv::VideoCaptureAPIs> backends = cv::videoio_registry::getStreamBackends();
+    bool requireFFmpeg = cv::utils::getConfigurationParameterBool("OPENCV_TEST_VIDEOIO_BACKEND_REQUIRE_FFMPEG");
+    if (requireFFmpeg && !isBackendAvailable(cv::CAP_FFMPEG, backends))
+    {
+        CV_LOG_FATAL(NULL, "OpenCV-Test: required FFmpeg backend is not available (broken plugin?). STOP.");
+        exit(1);
+    }
+}
+
+CV_TEST_MAIN("highgui", initTests())