Attributes are now allowed on if and if let

This became possible with rust-lang/rust#69201

Author: Aaron1011

src/expressions.md

@@ -272,11 +272,10 @@ a few specific cases:
         https://github.com/rust-lang/rust/issues/15701
   -->
 * The tail expression of [block expressions].
+* [`if`][_IfExpression_] and [`if let`][_IfLetExpression_] expressions.
 <!-- Keep list in sync with block-expr.md -->
 
 They are never allowed before:
-
-* [`if`][_IfExpression_] and [`if let`][_IfLetExpression_] expressions.
 * [Range][_RangeExpression_] expressions.
 * Binary operator expressions ([_ArithmeticOrLogicalExpression_],
   [_ComparisonExpression_], [_LazyBooleanExpression_], [_TypeCastExpression_],