Don't run tls13encryptiontest on a shared Windows build

tls13encryptiontest is an "internal" test. As with all the other internal
tests it should not be run on a shared native Windows build.

[extended tests]
Reviewed-by: NRichard Levitte <levitte@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/5266)

test/recipes/90-test_tls13encryption.t

@@ -15,6 +15,9 @@ setup($test_name);
 plan skip_all => "$test_name is not supported in this build"
     if disabled("tls1_3");
 
+plan skip_all => "This test is unsupported in a shared library build on Windows"
+    if $^O eq 'MSWin32' && !disabled("shared");
+
 plan tests => 1;
 
 ok(run(test(["tls13encryptiontest"])), "running tls13encryptiontest");