Add fallback for random number generator

`getrandom()` is available since Linux 3.17 (2014/10/05) yet there are older devices that don't
meet this requirement.

Closes #22691.
PR #22723.

src/base/utils/randomlayer_win.cpp

@@ -60,7 +60,7 @@ namespace
             return std::numeric_limits<result_type>::max();
         }
 
-        result_type operator()()
+        result_type operator()() const
         {
             result_type buf = 0;
             const bool result = m_processPrng(reinterpret_cast<PBYTE>(&buf), sizeof(buf));