macOS: Reliably apply workaround for system curl 8.{3,4,5} LibreSSL backend

In commit f2596dfa0e (macOS: Work around bug in system curl 8.{3,4,5}
LibreSSL backend, 2024-07-16, v3.30.1~2^2) we tried to prefer
`secure-transport` on problematic versions of curl.  However, the
`curl_global_sslset` setting must be applied before every
`curl_global_init` call, not just the first one.  Otherwise a
second (or subsequent) download won't apply the work-around.

Source/CTest/cmCTestCurl.cxx

@@ -19,9 +19,8 @@ cmCTestCurl::cmCTestCurl(cmCTest* ctest)
   , CurlOpts(ctest)
 {
   this->SetProxyType();
-  cmCurlInitOnce();
   // In windows, this will init the winsock stuff
-  ::curl_global_init(CURL_GLOBAL_ALL);
+  cm_curl_global_init(CURL_GLOBAL_ALL);
   this->Curl = cm_curl_easy_init();
 }
 

Source/CTest/cmCTestSubmitHandler.cxx

@@ -171,9 +171,8 @@ bool cmCTestSubmitHandler::SubmitUsingHTTP(
     headers = ::curl_slist_append(headers, h.c_str());
   }
 
-  cmCurlInitOnce();
   /* In windows, this will init the winsock stuff */
-  ::curl_global_init(CURL_GLOBAL_ALL);
+  cm_curl_global_init(CURL_GLOBAL_ALL);
   cmCTestCurlOpts curlOpts(this->CTest);
   for (std::string const& file : files) {
     /* get a curl handle */