ctest: --stop-time fails in year 2038

While working on reproducible builds for openSUSE, I found that our cmake-4.1.1 package fails the CTestTestStopTime test when run on or after 2038-01-01.

My guess is that the Tests/CTestTestStopTime/GetDate.cmake code somehow gets an overflow in a signed 32-bit int.

The test log had:

 Test project /home/abuild/rpmbuild/BUILD/cmake-full-4.1.1-build/cmake-4.1.1/Tests/CTestTestStopTime 
     Start 1: TestSleep
 1/2 Test #1: TestSleep ........................   Passed   30.00 sec
     Start 2: ShouldNotRun
 2/2 Test #2: ShouldNotRun .....................***Failed   30.00 sec

 50% tests passed, 1 tests failed out of 2

 Total Test time (real) =  60.00 sec

 The following tests FAILED: 
          2 - ShouldNotRun (Failed)

         Start 221: CTestTestSubdir