[lldb][test] Remove Windows xfail from 2 tests in TestLongjmp.py (#185859)
Started passing when #185464 landed.
https://lab.llvm.org/buildbot/#/builders/211/builds/6880
UNEXPECTED SUCCESS: test_step_back_out_dwarf
(TestLongjmp.LongjmpTestCase.test_step_back_out_dwarf)
Test stepping when the inferior calls setjmp/longjmp, in particular,
thread step-out after thread step-in.
UNEXPECTED SUCCESS: test_step_out_dwarf
(TestLongjmp.LongjmpTestCase.test_step_out_dwarf)
Test stepping when the inferior calls setjmp/longjmp, in particular,
thread step-out.
(test_step_over is still expectedly failing)