Partially fix some python tests (bug#59477)

This fixes

python-font-lock-assignment-statement-multiline-1
python-font-lock-assignment-statement-multiline-2
python-font-lock-assignment-statement-multiline-3
python-font-lock-assignment-statement-multiline-4
python-font-lock-assignment-statement-multiline-5
python-font-lock-assignment-statement-multiline-6

but leaves

python-tests--fill-long-first-line

unfixed.

* lisp/progmodes/python.el (python-mode): Add the missing setup.

1 files changed, 3 insertions, 1 deletions

diff --git a/lisp/progmodes/python.el b/lisp/progmodes/python.el
index 2a7e8a4081d..9bbcac612fd 100644
--- a/lisp/progmodes/python.el
+++ b/lisp/progmodes/python.el
@@ -6598,7 +6598,9 @@ implementations: `python-mode' and `python-ts-mode'."
               `(,python-font-lock-keywords
                 nil nil nil nil
                 (font-lock-syntactic-face-function
-                 . python-font-lock-syntactic-face-function)))
+                 . python-font-lock-syntactic-face-function)
+                (font-lock-extend-after-change-region-function
+                 . python-font-lock-extend-region)))
   (setq-local syntax-propertize-function
               python-syntax-propertize-function)
   (setq-local imenu-create-index-function