OpenSSL TLS plugin is not loaded for OpenSSLv3

The QSslSocket::availableBackends() methods doesn't return 'openssl' in the list of available backends, even though the corresponding DLLs (libssl-3-x64.dll and libcrypto-3-x64.dll) are located inside the library search path.

The reason for that is the loadOpenSsl() implementation for Q_OS_WIN in qsslsocket_openssl_symbols.cpp which assumes that the DLLs are named
libssl-1_1<suffix>
and
libcrypto-1_1<suffix>
This should be fixed to use the proper version number depending on the OpenSSL version Qt has been compiled against.