Revert "Drop 3.10 to use new datetime API"

This reverts commit c47ae7b.

Author: hugovk

.github/workflows/test.yml

@@ -14,7 +14,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        python-version: ["pypy3.11", "3.11", "3.12", "3.13", "3.14"]
+        python-version: ["pypy3.11", "3.10", "3.11", "3.12", "3.13", "3.14"]
         os: [ubuntu-latest]
 
     steps:

pyproject.toml

@@ -1,5 +1,5 @@
 [tool.black]
-target_version = [ "py311" ]
+target_version = [ "py310" ]
 
 [tool.ruff]
 fix = true