[FLINK-23345][python] Limits the version requests to 2.26.0 or above

This closes #17219.

Author: dianfu

flink-python/setup.py

@@ -312,6 +312,7 @@ def extracted_output_files(base_dir, file_path, output_directory):
                           'cloudpickle==1.2.2', 'avro-python3>=1.8.1,!=1.9.2,<1.10.0',
                           'pandas>=1.0,<1.2.0', 'pyarrow>=0.15.1,<3.0.0',
                           'pytz>=2018.3', 'numpy>=1.14.3,<1.20', 'fastavro>=0.21.4,<0.24',
+                          'requests>=2.26.0',
                           apache_flink_libraries_dependency],
         cmdclass={'build_ext': build_ext},
         tests_require=['pytest==4.4.1'],