message: build(riscv): suppress massive -Wignored-attributes warnings
diff: #include <vector>
  #include <opencv2/core/check.hpp>
  +#if defined(__GNUC__) && !defined(__clang__)
  +// FIXIT: eliminate massive warnigs from templates
  +// GCC from 'rvv-next': riscv64-unknown-linux-gnu-g++ (g42df3464463) 12.0.1 20220505 (prerelease)
  +// doesn't work: #pragma GCC diagnostic push
  +#pragma GCC diagnostic ignored "-Wignored-attributes"
  +#endif
  +
  #ifndef CV_RVV_MAX_VLEN
  #define CV_RVV_MAX_VLEN 1024
  #endif
  