ci: keep the dev lock installable on Python 3.11

contourpy 1.4.0 and numpy 2.5.3 require Python >=3.12, so the 3.11 CI
job has failed at install since the lock landed while pyproject still
declares >=3.11. Pin the newest 3.11-compatible releases via markers.

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Co-Authored-By: Devin <158243242+devin-ai-integration[bot]@users.noreply.github.com>

Author: xxg1413

requirements-dev.lock.txt

@@ -10,12 +10,14 @@ pytest==9.1.1
 referencing==0.37.0
 rpds-py==2026.6.3
 ruff==0.16.9
-contourpy==1.4.0
+contourpy==1.4.0; python_version >= "3.12"
+contourpy==1.3.3; python_version < "3.12"
 cycler==0.12.1
 fonttools==4.65.0
 kiwisolver==1.5.1
 matplotlib==3.10.9
-numpy==2.5.3
+numpy==2.5.3; python_version >= "3.12"
+numpy==2.4.6; python_version < "3.12"
 pandas==2.3.3
 pillow==12.3.0
 pyparsing==3.3.2