feat: move timezone preference to config file (#2096)

BREAKING CHANGE: The timezone preference moved to the configuration
file.

shared/setup.py

@@ -10,6 +10,7 @@ setup(
     packages=find_packages(exclude=["*tests*", "*fixtures*"]),
     package_data={"": ["py.typed"]},
     install_requires=[
+        "backports.zoneinfo>=0.2.1,<0.3;python_version<'3.9'",
         "click~=8.0.4",
         "loguru==0.6.0",
         "pydantic>=1.7.4,<1.11",
@@ -17,6 +18,7 @@ setup(
     ],
     extras_require={
         "dev": [
+            "types-backports",
             "types-pyyaml",
         ],
     },