Unreviewed, fix the build after rdar://115730279

After the changes for rdar://115730279, libnetcore's `nw_proxy_config_create_with_agent_data` now
takes an additional nullable outparam. Add a compile-time guard for this version of the SPI, and
use it to soft link (and call the soft-linked function) with or without this extra argument.

* Source/WTF/wtf/PlatformHave.h:
* Source/WebKit/NetworkProcess/cocoa/NetworkSessionCocoa.mm:
(WebKit::NetworkSessionCocoa::setProxyConfigData):

Canonical link: https://commits.webkit.org/269221@main

Source/WTF/wtf/PlatformHave.h

@@ -1643,3 +1643,11 @@
     || (PLATFORM(APPLETV) && __TV_OS_VERSION_MIN_REQUIRED >= 170000)
 #define HAVE_NSURL_ENCODING_INVALID_CHARACTERS 1
 #endif
+
+#if ((PLATFORM(MAC) && __MAC_OS_X_VERSION_MAX_ALLOWED >= 140200) \
+    || ((PLATFORM(MACCATALYST) || PLATFORM(IOS)) && __IPHONE_OS_VERSION_MAX_ALLOWED >= 170200) \
+    || (PLATFORM(WATCHOS) && __WATCH_OS_VERSION_MAX_ALLOWED >= 100200) \
+    || (PLATFORM(APPLETV) && __TV_OS_VERSION_MAX_ALLOWED >= 170200) \
+    || (PLATFORM(VISION) && __XR_OS_VERSION_MAX_ALLOWED >= 10200))
+#define HAVE_PROXY_CONFIG_CREATE_WITH_AGENT_DATA_WITH_RETURN_IS_COMPLETE 1
+#endif

Source/WebKit/NetworkProcess/cocoa/NetworkSessionCocoa.mm

@@ -101,7 +101,11 @@
 SOFT_LINK_LIBRARY_OPTIONAL(libnetwork)
 SOFT_LINK_OPTIONAL(libnetwork, nw_context_add_proxy, void, __cdecl, (nw_context_t, nw_proxy_config_t))
 SOFT_LINK_OPTIONAL(libnetwork, nw_context_clear_proxies, void, __cdecl, (nw_context_t))
+#if HAVE(PROXY_CONFIG_CREATE_WITH_AGENT_DATA_WITH_RETURN_IS_COMPLETE)
+SOFT_LINK_OPTIONAL(libnetwork, nw_proxy_config_create_with_agent_data, nw_proxy_config_t, __cdecl, (const uint8_t*, size_t, const uuid_t, bool*))
+#else
 SOFT_LINK_OPTIONAL(libnetwork, nw_proxy_config_create_with_agent_data, nw_proxy_config_t, __cdecl, (const uint8_t*, size_t, const uuid_t))
+#endif
 SOFT_LINK_OPTIONAL(libnetwork, nw_proxy_config_stack_requires_http_protocols, bool, __cdecl, (nw_proxy_config_t))
 #endif
 
@@ -2216,7 +2220,11 @@ void didCompleteWithError(const WebCore::ResourceError& error, const WebCore::Ne
         memcpy(identifier, config.second.toSpan().data(), sizeof(uuid_t));
 
 #if __has_include(<Network/proxy_config_private.h>)
-        auto nwProxyConfig = adoptNS(createProxyConfig(config.first.data(), config.first.size(), identifier));
+        auto nwProxyConfig = adoptNS(createProxyConfig(config.first.data(), config.first.size(), identifier
+#if HAVE(PROXY_CONFIG_CREATE_WITH_AGENT_DATA_WITH_RETURN_IS_COMPLETE)
+            , nullptr
+#endif
+        ));
 
         if (requiresHTTPProtocols(nwProxyConfig.get()))
             recreateSessions = true;