pin dateutil to git to avoid deprecation warning

Author: davidhewitt

tests/requirements.txt

@@ -1,6 +1,9 @@
 coverage==7.2.7
 dirty-equals==0.6.0
 hypothesis==6.79.4
+# TODO: remove manual override for dateutil once a version newer than 2.8.2 is
+# released which removes use of deprecated utcfromtimestamp
+git+https://github.com/dateutil/dateutil.git@f2293200747fb03d56c6c5997bfebeabe703576f
 # pandas doesn't offer prebuilt wheels for all versions and platforms we test in CI e.g. aarch64 musllinux
 pandas==2.1.3; python_version >= "3.9" and python_version < "3.13" and implementation_name == "cpython" and platform_machine == 'x86_64'
 pytest==7.4.3