Fix #19134 by adding images.clear to the two sync codepaths for Opencl Kernel run.

Passed all tests in opencv_test_cored.exe

[----------] Global test environment tear-down
[ SKIPSTAT ] 34 tests skipped
[ SKIPSTAT ] TAG='mem_6gb' skip 1 tests
[ SKIPSTAT ] TAG='skip_bigdata' skip 1 tests
[ SKIPSTAT ] TAG='skip_other' skip 32 tests
[==========] 11608 tests from 245 test cases ran. (420102 ms total)
[  PASSED  ] 11608 tests.

  YOU HAVE 19 DISABLED TESTS

Passed all tests in opencv_test_imgprocd.exe

[----------] Global test environment tear-down
[ SKIPSTAT ] 2 tests skipped
[ SKIPSTAT ] TAG='skip_bigdata' skip 2 tests
[==========] 10239 tests from 202 test cases ran. (377291 ms total)
[  PASSED  ] 10239 tests.

  YOU HAVE 5 DISABLED TESTS

Pull Request Readiness Checklist

• I agree to contribute to the project under Apache 2 License.
• To the best of my knowledge, the proposed patch is not based on a code under GPL or other license that is incompatible with OpenCV
• The PR is proposed to proper branch
• There is reference to original bug report and related work
• There is accuracy test, performance test and test data in opencv_extra repository, if applicable
  Patch to opencv_extra has the same branch name.
• The feature is well documented and sample code can be built with the project CMake