lang/dotnet: Get rid of security/openssl dependency

This required rebuilding bootstrap binaries against base OpenSSL.

Unfortunately, libraries from the bootstrap distribution are linked into
programs being built by the port. This puts us into an ABI conflict between
OpenSSL 1.1.1 from FreeBSD 13 base and OpenSSL 3 from FreeBSD 14 base [1].
This is probably a bug of .NET build system, but for now just use different
bootstraps for FreeBSD 13 and 14.

[1]:
ld.lld : error : undefined symbol: ERR_put_error

referenced by pal_evp.c.o:(CryptoNative_EvpMdCtxCreate) in archive /wrkdirs/usr/ports/lang/dotnet/work/bootstrap_sdk/packs/runtime.freebsd.13-x64.Microsoft.DotNet.ILCompiler/9.0.0/framework/libSystem.Security.Cryptography.Native.OpenSsl.a

clang-15 : error : linker command failed with exit code 1 (use -v to see invocation)

The command ""/usr/local/bin/clang15" "/wrkdirs/usr/ports/lang/dotnet/work/dotnet-9.0.2/src/runtime/artifacts/obj/coreclr/ILCompiler/freebsd.x64.Release/native/ilc.o" -o "/wrkdirs/usr/ports/lang/dotnet/work/dotnet-9.0.2/src/runtime/artifacts/bin/coreclr/freebsd.x64.Release/ilc/native/ilc" ... /wrkdirs/usr/ports/lang/dotnet/work/bootstrap_sdk/packs/runtime.freebsd.13-x64.Microsoft.DotNet.ILCompiler/9.0.0/framework/libSystem.Security.Cryptography.Native.OpenSsl.a ...