CI: Update flake8 test, apply fix

.github/workflows/contrib.yml

@@ -11,15 +11,13 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v4
         with:
           submodules: recursive
           fetch-depth: 0
-      - name: Set up Python 3.9
-        uses: actions/setup-python@v2
+      - name: Set up Python 3
+        uses: actions/setup-python@v5
         with:
-          python-version: 3.9
-      - name: Install flake8
-        run: python -m pip install flake8
-      - name: Check EddyMotion
-        run: python -m flake8 src
+          python-version: 3
+      - name: Lint EddyMotion
+        run: pipx run flake8-pyproject

test/test_estimator.py

@@ -77,4 +77,4 @@ def test_ANTs_config_b0(datadir, tmp_path, r_x, r_y, r_z, t_x, t_y, t_z):
 
     coords = xfm.reference.ndcoords.T
     rms = np.sqrt(((xfm.map(coords) - xform.map(coords)) ** 2).sum(1)).mean()
-    assert  rms < 0.8
+    assert rms < 0.8