Drop Python 3.8 support (fox-it#149)

As Python 3.8 is now officially EOL, minimal required version is now Python 3.9.

pyproject.toml

@@ -6,7 +6,7 @@ build-backend = "setuptools.build_meta"
 name = "flow.record"
 description = "A library for defining and creating structured data (called records) that can be streamed to disk or piped to other tools that use flow.record"
 readme = "README.md"
-requires-python = "~=3.8"
+requires-python = "~=3.9"
 license.text = "Affero General Public License v3"
 authors = [
   {name = "Dissect Team", email = "[email protected]"}
@@ -24,7 +24,6 @@ classifiers = [
 ]
 dependencies = [
     "msgpack>=0.5.2",
-    "backports.zoneinfo[tzdata]; python_version<'3.9'",
     "tzdata; platform_system=='Windows'",
 ]
 dynamic = ["version"]

tox.ini

@@ -50,7 +50,7 @@ deps =
     vermin
 commands =
     flake8 flow tests
-    vermin -t=3.8- --no-tips --lint --exclude zoneinfo flow tests
+    vermin --target=3.9 --no-tips --lint flow tests
 
 [flake8]
 max-line-length = 120