Fix build on cygwin

Fixes #19531
Reviewed-by: NTodd Short <todd.short@me.com>
Reviewed-by: NTomas Mraz <tomas@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/21006)

Configurations/10-main.conf

@@ -1717,6 +1717,7 @@ my %targets = (
         CFLAGS           => picker(default => "-Wall",
                                    debug   => "-g -O0",
                                    release => "-O3"),
+        ex_libs          => add("-lcrypt32"),
         lib_cppflags     => "-DTERMIOS -DL_ENDIAN",
         sys_id           => "CYGWIN",
         thread_scheme    => "pthread",

providers/implementations/storemgmt/winstore_store.c

@@ -23,7 +23,9 @@
 #include "prov/implementations.h"
 #include "prov/bio.h"
 #include "file_store_local.h"
-
+#ifdef __CYGWIN__
+#include <Windows.h>
+#endif
 #include <wincrypt.h>
 
 enum {