Revert "implement fixture isolation"

This reverts commit 0366835, there seem
to be some issues with fixture teardown order

boa/test/plugin.py

@@ -1,5 +1,4 @@
 import contextlib
-import warnings
 from typing import Generator
 
 import hypothesis
@@ -51,23 +50,6 @@ def pytest_collection_modifyitems(config, items):
                 item.add_marker("gas_profile")
 
 
-_fixture_map = {}
-
-
-def pytest_fixture_setup(fixturedef, request):
-    ctx = boa.env.anchor()
-    assert id(fixturedef) not in _fixture_map, "bad invariant"
-    _fixture_map[id(fixturedef)] = ctx
-    ctx.__enter__()
-
-
-def pytest_fixture_post_finalizer(fixturedef, request):
-    if (ctx := _fixture_map.pop(id(fixturedef), None)) is not None:
-        ctx.__exit__(None, None, None)
-    else:
-        warnings.warn("possible bug in titanoboa! bad fixture tracking", stacklevel=1)
-
-
 @pytest.hookimpl(hookwrapper=True)
 def pytest_runtest_call(item: pytest.Item) -> Generator:
     ignore_isolation = item.get_closest_marker("ignore_isolation") is not None

tests/unitary/test_isolation.py

@@ -66,16 +66,3 @@ def setup_ignore_isolation(boa_contract):
 def test_check_ignore_isolation(boa_contract, setup_ignore_isolation):
     assert boa_contract.a() == 42069
     assert boa_contract.b() == addr_constn
-
-
-@pytest.fixture(scope="function")
-def modify_boa_contract(boa_contract):
-    # these values spill over from the previous test
-    assert boa_contract.a() == 42069
-    assert boa_contract.b() == addr_constn
-    boa_contract.set_vars(boa_contract.a() + 1, boa.env.generate_address())
-
-
-@pytest.mark.parametrize("a", range(10))
-def test_fixture_isolation(modify_boa_contract, a):
-    pass