Release: Increase timeout for slow-testing cygwin build

The parent commit only added DART_TESTING_TIMEOUT to the cache.
Also add CTEST_TEST_TIMEOUT because the logic in
CMake/Tests/CMakeLists.txt uses that variable in its "long test
timeout" computation. Now the cygwin build really does have 7200
seconds before it calls timeout death on a test.

Utilities/Release/dash2win64_cygwin.cmake

@@ -8,6 +8,7 @@ set(CPACK_SOURCE_GENERATORS "CygwinSource")
 set(MAKE_PROGRAM "make")
 set(INITIAL_CACHE "CMAKE_BUILD_TYPE:STRING=Release
 CMAKE_Fortran_COMPILER_FULLPATH:FILEPATH=FALSE
+CTEST_TEST_TIMEOUT:STRING=7200
 DART_TESTING_TIMEOUT:STRING=7200
 ")
 set(CXX g++)