Update preferred TYPO3 core version to 14.3

Author: linawolf

Documentation/guides.xml

@@ -8,7 +8,7 @@
                project-repository="https://github.com/TYPO3-Documentation/DocsTypo3Org-Homepage"
                project-issues="https://github.com/TYPO3-Documentation/DocsTypo3Org-Homepage/issues"
                edit-on-github-branch="main" edit-on-github="TYPO3-Documentation/DocsTypo3Org-Homepage"
-               typo3-core-preferred="stable"
+               typo3-core-preferred="14.3"
                interlink-shortcode="t3docs"
                disable-version-switch="true"
     />