Update old reference to Base.REPL (#29910)

(cherry picked from commit 0999799)

stdlib/REPL/docs/src/index.md

@@ -47,7 +47,7 @@ In Julia mode, the REPL supports something called *prompt pasting*. This activat
 text that starts with `julia> ` into the REPL. In that case, only expressions starting with
 `julia> ` are parsed, others are removed. This makes it is possible to paste a chunk of code
 that has been copied from a REPL session without having to scrub away prompts and outputs. This
-feature is enabled by default but can be disabled or enabled at will with `Base.REPL.enable_promptpaste(::Bool)`.
+feature is enabled by default but can be disabled or enabled at will with `REPL.enable_promptpaste(::Bool)`.
 If it is enabled, you can try it out by pasting the code block above this paragraph straight into
 the REPL. This feature does not work on the standard Windows command prompt due to its limitation
 at detecting when a paste occurs.