[doc] Add a missing apostrophe in a code example in venv.rst (GH-28391) (GH-28425)

(cherry picked from commit d22a700091af35ce52db0b1fbb02115bb6efbb1f)

Co-authored-by: Arkaprabha Chakraborty <chakrabortyarkaprabha998@gmail.com>
1 file changed