Remove vcpkg workaround from ProvideCurl.cmake

According to these links the issue should be fixed and the workaround
no longer necessary:

* microsoft/vcpkg#3220
* microsoft/vcpkg#1909

Author: Grumbel

mk/cmake/SuperTux/ProvideCurl.cmake

@@ -4,21 +4,6 @@
 if(NOT EMSCRIPTEN)
   find_package(CURL REQUIRED)
 
-  if(WIN32 AND VCPKG_BUILD)
-    list(LENGTH CURL_LIBRARY CURL_LIBRARY_LENGTH)
-    if(CURL_LIBRARY_LENGTH EQUAL 1)
-      set(CURL_LIBRARY_DEBUG_LIB   ${CURL_LIBRARY})
-      set(CURL_LIBRARY_RELEASE_LIB ${CURL_LIBRARY_DEBUG_LIB}/../../../lib/libcurl.lib)
-      get_filename_component(CURL_LIBRARY_RELEASE_LIB ${CURL_LIBRARY_RELEASE_LIB} REALPATH)
-      unset(CURL_LIBRARY CACHE)
-      unset(CURL_LIBRARY)
-      unset(CURL_LIBRARIES  CACHE)
-      unset(CURL_LIBRARIES)
-      set(CURL_LIBRARY "debug;${CURL_LIBRARY_DEBUG_LIB};optimized;${CURL_LIBRARY_RELEASE_LIB}")
-      set(CURL_LIBRARIES ${CURL_LIBRARY})
-    endif()
-  endif()
-
   add_library(LibCurl INTERFACE IMPORTED)
   set_target_properties(LibCurl PROPERTIES
     INTERFACE_INCLUDE_DIRECTORIES "${CURL_INCLUDE_DIRS}")