[BUGFIX] Add 10.4.x changelogs to index as well

Resolves: #91308
Releases: master
Change-Id: I1dc74ba54e11f35e0d4b99ebcc68e1ee77ea8598
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/64410
Reviewed-by: Benjamin Franzke <bfr@qbus.de>
Reviewed-by: Helmut Hummel <typo3@helhum.io>
Reviewed-by: Daniel Siepmann <coding@daniel-siepmann.de>
Tested-by: Helmut Hummel <typo3@helhum.io>
Tested-by: Daniel Siepmann <coding@daniel-siepmann.de>

typo3/sysext/core/Documentation/Changelog-10.rst

@@ -16,3 +16,4 @@ Every change to the TYPO3 Core which might affect your site is documented here.
    Changelog/10.2/Index
    Changelog/10.3/Index
    Changelog/10.4/Index
+   Changelog/10.4.x/Index