Bump test tooling versions, and fix poly unit tests.

pyproject.toml

@@ -72,8 +72,8 @@ include = [
 dependencies = [
     'formulaic[arrow,calculus]; python_version < "3.11"',
     'formulaic[calculus]; python_version == "3.11"',
-    "pytest==6.2.5",
-    "pytest-cov==3.0.0",
+    "pytest==7.2.0",
+    "pytest-cov==4.0.0",
 ]
 
 [tool.hatch.envs.default.scripts]
@@ -88,8 +88,8 @@ python = ["37"]
 [tool.hatch.envs.test_min]
 dependencies = [
     "formulaic[arrow,calculus]",
-    "pytest==6.2.5",
-    "pytest-cov==3.0.0",
+    "pytest==7.2.0",
+    "pytest-cov==4.0.0",
     "astor==0.8",
     "cached-property==1.3.0; python_version < \"3.8\"",
     "graphlib-backport==1.0.0; python_version < \"3.9\"",

tests/transforms/test_poly.py

@@ -47,8 +47,8 @@ def test_basic(self, data):
             r_reference,
         )
 
-        assert pytest.approx(state["alpha"], {0: 0.5})
-        assert pytest.approx(state["norms2"], {0: 21.0, 2: 1.925})
+        assert state["alpha"] == pytest.approx({0: 0.5})
+        assert state["norms2"] == pytest.approx({0: 21.0, 1: 1.925})
 
         assert numpy.allclose(
             poly(data, _state=state)[:, 0],
@@ -95,9 +95,9 @@ def test_degree(self, data):
             r_reference,
         )
 
-        assert pytest.approx(state["alpha"], {0: 0.5, 1: 0.5, 2: 0.5})
-        assert pytest.approx(
-            state["norms2"], {1: 0.09166666666666667, 2: 0.07283333333333333}
+        assert state["alpha"] == pytest.approx({0: 0.5, 1: 0.5, 2: 0.5})
+        assert state["norms2"] == pytest.approx(
+            {0: 21.0, 1: 1.925, 2: 0.14020416666666669, 3: 0.009734175}
         )
 
         assert numpy.allclose(