remove test sched

tests/graph/test_sched.py

-from pytensor.graph.basic import io_toposort
-from pytensor.graph.sched import (
-    _toposort,
-    make_dependence_cmp,
-    posort,
-    reverse_dict,
-    sort_apply_nodes,
-)
-from pytensor.tensor.math import dot
-from pytensor.tensor.type import matrix
-from pytensor.utils import cmp
-
-
-def test_dependence():
-    dependence = make_dependence_cmp()
-
-    x = matrix("x")
-    y = dot(x * 2, x + 1)
-    nodes = io_toposort([x], [y])
-
-    for a, b in zip(nodes[:-1], nodes[1:]):
-        assert dependence(a, b) <= 0
-
-
-def test_sort_apply_nodes():
-    x = matrix("x")
-    y = dot(x * 2, x + 1)
-
-    def str_cmp(a, b):
-        return cmp(str(a), str(b))  # lexicographical sort
-
-    nodes = sort_apply_nodes([x], [y], cmps=[str_cmp])
-
-    for a, b in zip(nodes[:-1], nodes[1:]):
-        assert str(a) <= str(b)
-
-
-def test_reverse_dict():
-    d = {"a": (1, 2), "b": (2, 3), "c": ()}
-    # Python 3.3 enable by default random hash for dict.
-    # This change the order of traversal, so this can give 2 outputs
-    assert reverse_dict(d) == {1: ("a",), 2: ("a", "b"), 3: ("b",)} or reverse_dict(
-        d
-    ) == {1: ("a",), 2: ("b", "a"), 3: ("b",)}
-
-
-def test__toposort():
-    edges = {
-        1: {4, 6, 7},
-        2: {4, 6, 7},
-        3: {5, 7},
-        4: {6, 7},
-        5: {7},
-    }
-    order = _toposort(edges)
-    assert not any(
-        a in edges.get(b, ()) for i, a in enumerate(order) for b in order[i:]
-    )
-
-
-def test_posort_easy():
-    nodes = "asdfghjkl"
-
-    def mycmp(a, b):
-        if a < b:
-            return -1
-        elif a > b:
-            return 1
-        else:
-            return 0
-
-    assert posort(nodes, mycmp) == list("adfghjkls")
-
-
-def test_posort():
-    l = list(range(1, 20))
-    cmps = [
-        lambda a, b: a % 10 - b % 10,
-        lambda a, b: (a / 10) % 2 - (b / 10) % 2,
-        lambda a, b: a - b,
-    ]
-    assert posort(l, *cmps) == [
-        10,
-        1,
-        11,
-        2,
-        12,
-        3,
-        13,
-        4,
-        14,
-        5,
-        15,
-        6,
-        16,
-        7,
-        17,
-        8,
-        18,
-        9,
-        19,
-    ]