Merge bitcoin/bitcoin#29786: Drop Windows Socket dependency for randomenv.cpp

03b87a3 Drop Windows Socket dependency for `randomenv.cpp` (Hennadii Stepanov)

Pull request description:

  This change drops a dependency on the ws2_32 library for our libbitcoinkernel by switching to [`GetComputerName`](https://learn.microsoft.com/en-us/windows/win32/api/winbase/nf-winbase-getcomputernamew) function.

ACKs for top commit:
  sipsorcery:
    utACK 03b87a3.
  laanwj:
    Code review ACK 03b87a3.
  fanquake:
    ACK 03b87a3

Tree-SHA512: a4abd5499176634d5f3fbf4e794a7504c40232fb73bd7f41955fbfb2cc7c44bc7ea4518c5203836e52f552c30414c6c3e1b24f0922641dbf1c8377981c0ffaf0

Author: fanquake

src/randomenv.cpp

@@ -13,6 +13,7 @@
 #include <compat/compat.h>
 #include <compat/cpuid.h>
 #include <crypto/sha512.h>
+#include <span.h>
 #include <support/cleanse.h>
 #include <util/time.h>
 
@@ -357,10 +358,19 @@ void RandAddStaticEnv(CSHA512& hasher)
     hasher << &hasher << &RandAddStaticEnv << &malloc << &errno << &environ;
 
     // Hostname
+#ifdef WIN32
+    constexpr DWORD max_size = MAX_COMPUTERNAME_LENGTH + 1;
+    char hname[max_size];
+    DWORD size = max_size;
+    if (GetComputerNameA(hname, &size) != 0) {
+        hasher.Write(UCharCast(hname), size);
+    }
+#else
     char hname[256];
     if (gethostname(hname, 256) == 0) {
         hasher.Write((const unsigned char*)hname, strnlen(hname, 256));
     }
+#endif
 
 #if HAVE_DECL_GETIFADDRS && HAVE_DECL_FREEIFADDRS
     // Network interfaces