[UR] `std::vector` is copied unnecessary in leak check

[AlexeySachkov]

llvm/unified-runtime/source/loader/layers/validation/ur_leak_check.hpp

Lines 28 to 30 in 64ceadc

	RefRuntimeInfo(int64_t refCount, std::type_index type,
	std::vector<BacktraceLine> backtrace)
	: refCount(refCount), type(type), backtrace(backtrace) {}

If I understand correctly, multiple copies are being done here: once when we invoke the constructor and then within the constructor itself. Considering that this is a debugging thing/layer I don't think that the impact is significant, but still nice to fix.

Reported by Coverity as CID 443321