Allow boolean positionals in __post_init__ (#10027)

Closes https://github.com/astral-sh/ruff/issues/10011.

crates/ruff_linter/resources/test/fixtures/flake8_boolean_trap/FBT.py

@@ -119,3 +119,16 @@ def func(x: bool):
 
 
 settings(True)
+
+
+from dataclasses import dataclass, InitVar
+
+
+@dataclass
+class Fit:
+    force: InitVar[bool] = False
+
+    def __post_init__(self, force: bool) -> None:
+        print(force)
+
+Fit(force=True)

crates/ruff_linter/src/rules/flake8_boolean_trap/helpers.rs

@@ -45,7 +45,7 @@ pub(super) fn is_allowed_func_call(name: &str) -> bool {
 
 /// Returns `true` if a function definition is allowed to use a boolean trap.
 pub(super) fn is_allowed_func_def(name: &str) -> bool {
-    matches!(name, "__setitem__")
+    matches!(name, "__setitem__" | "__post_init__")
 }
 
 /// Returns `true` if an argument is allowed to use a boolean trap. To return