Use CURLSSLOPT_NATIVE_CA to rely on the Windows native CA

[coryan]

With recent (>= 7.71.0) versions of libcurl one can use the native CA on Windows:

https://stackoverflow.com/questions/37551409/configure-curl-to-use-default-system-cert-store-on-windows https://curl.se/libcurl/c/CURLOPT_SSL_OPTIONS.html

We need to make sure this still works when libcurl was compiled against Schannel, but that seems like a reasonably safe bet.

[devjgm]

Keeping open, but can't do it now.

[coryan]

Strike two.

[coryan]

No time for this, to the backlog.