Delete redundant words Running R code section (#1148)

At the and of Running R Code section the "we'll use" are written 2 times.

intro.qmd

@@ -251,7 +251,7 @@ Throughout the book, we use a consistent set of conventions to refer to code:
 
 -   Other R objects (such as data or function arguments) are in a code font, without parentheses, like `flights` or `x`.
 
--   Sometimes, to make it clear which package an object comes from, we'll use we'll use the package name followed by two colons, like `dplyr::mutate()`, or\
+-   Sometimes, to make it clear which package an object comes from, we'll use the package name followed by two colons, like `dplyr::mutate()`, or\
     `nycflights13::flights`.
     This is also valid R code.