fix: use tomllib/tomli compat import for Python 3.10 (stdlib tomllib requires 3.11+)

Author: Coding-Dev-Tools

tests/test_edge_cases.py

@@ -9,7 +9,10 @@
 from io import StringIO
 from pathlib import Path
 
-import tomllib
+try:
+    import tomllib
+except ImportError:
+    import tomli as tomllib  # Python < 3.11 backport
 from rich.console import Console
 
 from deploydiff.cli import _load_plan, _render_costs
@@ -161,4 +164,4 @@ def test_ruff_known_first_party(self):
             data = tomllib.load(f)
         isort_cfg = data.get("tool", {}).get("ruff", {}).get("lint", {}).get("isort", {})
         kfp = isort_cfg.get("known-first-party", [])
-        assert kfp == ["deploydiff"], f"known-first-party should be ['deploydiff'], got {kfp}"
+        assert kfp == ["deploydiff"], f"known-first-party should be ['deploydiff'], got {kfp}"