Update dependency cython to v3.1.6 (#3682)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

flink-python/dev/dev-requirements.txt

@@ -16,7 +16,7 @@ pip>=20.3
 setuptools>=18.0
 wheel
 apache-beam==2.68.0
-cython==3.1.5
+cython==3.1.6
 py4j==0.10.9.9
 python-dateutil==2.9.0.post0
 cloudpickle==3.1.1

flink-python/pyproject.toml

@@ -22,7 +22,7 @@ requires = [
     "setuptools>=18.0",
     "wheel",
     "apache-beam==2.68.0",
-    "cython==3.1.5"
+    "cython==3.1.6"
 ]
 
 [tool.cibuildwheel]