Added Python tests to CUDA build for 4.x (#270)

Author: asmorkalov

.github/workflows/OCV-Contrib-PR-4.x-U20-Cuda.yaml

@@ -23,6 +23,7 @@ env:
   OPENCV_TEST_DATA_PATH: '/home/ci/opencv_extra/testdata'
   OPENCV_TEST_REQUIRE_DATA: 1
   OPENCV_CONTRIB_DOCKER_WORKDIR: '/home/ci/opencv_contrib'
+  PYTHONPATH: '/home/ci/build/python_loader:$PYTHONPATH'
   PARALLEL_JOBS: 8
 
 jobs:
@@ -42,7 +43,7 @@ jobs:
         - /usr/lib/x86_64-linux-gnu/libnvcuvid.so:/usr/lib/x86_64-linux-gnu/libnvcuvid.so
         - /usr/lib/x86_64-linux-gnu/libnvidia-encode.so:/usr/lib/x86_64-linux-gnu/libnvidia-encode.so
         - /usr/lib/x86_64-linux-gnu/libcuda.so.1:/usr/lib/x86_64-linux-gnu/libcuda.so
-        
+
     steps:
     - name: Brief system information
       timeout-minutes: 60
@@ -226,3 +227,7 @@ jobs:
       run: cd $HOME/build && xvfb-run -a bin/opencv_perf_cudawarping --perf_min_samples=1 --perf_force_samples=1 --perf_verify_sanity --skip_unstable=1 --perf_threads=${{ env.PARALLEL_JOBS }} --gtest_filter=${{ env.GTEST_FILTER_STRING }}
       env:
         GTEST_FILTER_STRING: '-Sz_Depth_Cn_Inter_Rotate.Rotate/7:Sz_Depth_Cn_Inter_Rotate.Rotate/34:Sz_Depth_Cn_Inter_Rotate.Rotate/55'
+    - name: Accuracy:python3
+      timeout-minutes: 60
+      if: ${{ always() && steps.build-opencv-contrib.outcome == 'success' }}
+      run: python3 $HOME/opencv/modules/python/test/test_cuda.py --repo $HOME/opencv -v