Docs: FIX broken links. (GH-13491)

(cherry picked from commit 7114c6504a60365b8b0cd718da0ec8a737599fb9)

Co-authored-by: Julien Palard <julien@palard.fr>
diff --git a/Doc/library/tkinter.rst b/Doc/library/tkinter.rst
index 60cf892..640fb2e 100644
--- a/Doc/library/tkinter.rst
+++ b/Doc/library/tkinter.rst
@@ -55,7 +55,7 @@
    `Tcl/Tk recent man pages <https://www.tcl.tk/doc/>`_
       Recent Tcl/Tk manuals on www.tcl.tk.
 
-   `ActiveState Tcl Home Page <http://tcl.activestate.com/>`_
+   `ActiveState Tcl Home Page <https://tcl.tk>`_
       The Tk/Tcl development is largely taking place at ActiveState.
 
    `Tcl and the Tk Toolkit <https://www.amazon.com/exec/obidos/ASIN/020163337X>`_