ci(3.14t): gate opencv-python into optional 'cv' group + skip cv2 files

opencv-python has no cp314t wheel yet and fails to build from source under
free-threaded 3.14t (CMake), blocking uv sync for every job. Move it to an
optional [dependency-groups] cv group so the ft CI installs everything else
and runs pytest-run-parallel on the pure-Python algorithms. Skip the 20 files
that import cv2 (computer_vision augmentations, data_compression PSNR, and the
mostly-cv2 digital_image_processing/ tree). Re-fold once a cp314t wheel ships
(upstream: opencv/opencv#27933).

Author: priya-sundaram-dev

.github/workflows/build.yml

@@ -22,9 +22,18 @@ jobs:
       - run: uv sync --group=test
       - name: Run tests
         # TODO: #8818 Re-enable quantum tests
+        # opencv-python is gated out on 3.14t (no cp314t wheel yet), so skip the
+        # files that import cv2. Pure-Python algorithms in computer_vision/ and
+        # data_compression/ still run; digital_image_processing/ is almost entirely
+        # cv2-based so it is skipped as a tree. Re-enable when a cp314t wheel ships.
         run: uv run --with=pytest-run-parallel pytest
           --iterations=8 --parallel-threads=auto
           --ignore=computer_vision/cnn_classification.py
+          --ignore=computer_vision/flip_augmentation.py
+          --ignore=computer_vision/harris_corner.py
+          --ignore=computer_vision/mosaic_augmentation.py
+          --ignore=data_compression/peak_signal_to_noise_ratio.py
+          --ignore=digital_image_processing/
           --ignore=docs/conf.py
           --ignore=dynamic_programming/k_means_clustering_tensorflow.py
           --ignore=machine_learning/local_weighted_learning/local_weighted_learning.py

pyproject.toml

@@ -18,7 +18,6 @@ dependencies = [
   "lxml>=6",
   "matplotlib>=3.9.3",
   "numpy>=2.1.3",
-  "opencv-python>=4.10.0.84",
   "pandas>=2.3.3",
   "pillow>=11.3",
   "rich>=13.9.4",
@@ -33,6 +32,14 @@ dependencies = [
 ]
 
 [dependency-groups]
+# opencv-python has no free-threaded (cp314t) wheel yet and fails to build from
+# source under 3.14t (CMake), which blocks `uv sync` for every job. Keep it in an
+# optional group so the free-threaded CI can install everything else and actually
+# run pytest-run-parallel on the pure-Python algorithms. Re-fold into core deps
+# once a cp314t wheel ships (upstream: opencv/opencv#27933).
+cv = [
+  "opencv-python>=4.10.0.84",
+]
 test = [
   "pytest>=8.4.1",
   "pytest-cov>=6",