build: Update dependencies and pre-commit hooks

Bump mypy to 2.3.1 and refresh all pre-commit hooks (ruff 0.16,
markdownlint 0.18). Fix issues surfaced by the new tooling:

- Use lowercase samesite cookie values (mypy 2.x)
- Remove no-op global declarations and address new ruff findings;
  ignore rules that would require behavior changes
- Add missing comma in AI system prompt (strings were concatenated)
- Wrap long README lines for MD013

pyproject.toml

@@ -23,7 +23,7 @@ rl-ai-tools = { source = "infomaniak" }
 
 [tool.poetry.group.dev.dependencies]
 types-requests = "^2.33.0.20260906"
-mypy = "^1.20.2"
+mypy = "^2.3.1"
 
 
 [[tool.poetry.source]]
@@ -31,6 +31,15 @@ name = "infomaniak"
 url = "https://pypi.purple.infomaniak.ch"
 priority = "supplemental"
 
+[tool.ruff.lint]
+ignore = [
+    "ASYNC210",
+    "BLE001",
+    "DTZ005",
+    "PLW1510",
+    "SIM115",
+]
+
 [build-system]
 requires = ["poetry-core"]
 build-backend = "poetry.core.masonry.api"