Fix #6739 test

There was an error in that test where you need a QuoteContext
in scope to write quotes. The error did not manifest itself since
a synthetic QuoteContext was generated for all inline methods
from which it was required (disregarding whether they are meant as
macro implementations or not). This behavior was wrong, however,
(see #7407) and hence this test needs fixing.

Author: anatoliykmetyuk

tests/neg/i6739.scala

@@ -3,4 +3,4 @@ import scala.quoted._
 inline def assert(expr: => Boolean): Unit =
   ${ assertImpl('expr) } // error: Macro cannot be implemented with an `inline` method
 
-inline def assertImpl(expr: Expr[Boolean]): Expr[Unit] = '{ println("Hello World") }
+inline def assertImpl(expr: Expr[Boolean])(given QuoteContext): Expr[Unit] = '{ println("Hello World") }