TST: add skips for weird special cases

Author: ev-br

array-api-tests-xfails.txt

@@ -3,6 +3,10 @@
 array_api_tests/test_special_cases.py::test_iop[__ipow__(x1_i is -infinity and x2_i > 0 and not (x2_i.is_integer() and x2_i % 2 == 1)) -> +infinity]
 array_api_tests/test_special_cases.py::test_iop[__ipow__(x1_i is -0 and x2_i > 0 and not (x2_i.is_integer() and x2_i % 2 == 1)) -> +0]
 
+# observed in releasing 2.3.1
+array_api_tests/test_special_cases.py::test_binary[floor_divide(x1_i is +infinity and isfinite(x2_i) and x2_i > 0) -> +infinity]
+array_api_tests/test_special_cases.py::test_binary[floor_divide(x1_i is +infinity and isfinite(x2_i) and x2_i < 0) -> -infinity]
+
 # The test suite is incorrectly checking sums that have loss of significance
 # (https://github.com/data-apis/array-api-tests/issues/168)
 array_api_tests/test_statistical_functions.py::test_sum