[`flake8-builtins`] Skip lambda expressions in `builtin-argument-shadowing (A002)` (#14144)
Flake8-builtins provides two checks for arguments (really, parameters)
of a function shadowing builtins: A002 checks function definitions, and
A006 checks lambda expressions. This PR ensures that A002 is restricted
to functions rather than lambda expressions.
Closes #14135 .