Fixes:

- Add missing virtual destructor on `SSLBackend`.

- On Windows, filter out `POLLWRBAND` (one of the new flags added) when
  calling `WSAPoll`, because despite the constant being defined on
  Windows, passing it calls `WSAPoll` to yield `EINVAL`.

- Reduce OpenSSL version requirement to satisfy CI; I haven't tested
  whether it actually builds (or runs) against 1.1.1, but if not, I'll
  figure it out.

- Change an instance of memcpy to memmove, even though the arguments
  cannot overlap, to avoid a [strange GCC
  error](https://github.com/yuzu-emu/yuzu/pull/10912#issuecomment-1606283351).

src/core/hle/service/sockets/sfdnsres.cpp

@@ -96,7 +96,7 @@ static void Append(std::vector<u8>& vec, T t) {
 static void AppendNulTerminated(std::vector<u8>& vec, std::string_view str) {
     size_t off = vec.size();
     vec.resize(off + str.size() + 1);
-    std::memcpy(vec.data() + off, str.data(), str.size());
+    std::memmove(vec.data() + off, str.data(), str.size());
 }
 
 // We implement gethostbyname using the host's getaddrinfo rather than the