[DOCS] Link to issues in category "Redirects Handling"

The redirects documentation contains a link to the issues on the
page "Known problems", using a category filter.

This used to be "Link Handling, Site Handling & Routing", but
redirects now have their own category "Redirects Handling", so
we use this.

Resolves: #101260
Releases: main, 12.4, 11.5
Change-Id: Ife6c4bbd7b2db1476054d5ce2558f84f32ab4800
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/79829


Tested-by: core-ci <typo3@b13.com>
Reviewed-by: Benni Mack <benni@typo3.org>
Tested-by: Benni Mack <benni@typo3.org>

typo3/sysext/redirects/Documentation/KnownProblems/Index.rst

@@ -5,5 +5,5 @@ Known problems
 ==============
 
 For known problems, please refer to the
-`open issues for "Link Handling, Site Handling & Routing"
-<https://forge.typo3.org/projects/typo3cms-core/issues?utf8=%E2%9C%93&set_filter=1&f%5B%5D=category_id&op%5Bcategory_id%5D=%3D&v%5Bcategory_id%5D%5B%5D=1598&f%5B%5D=status_id&op%5Bstatus_id%5D=o&f%5B%5D=&c%5B%5D=tracker&c%5B%5D=status&c%5B%5D=priority&c%5B%5D=subject&c%5B%5D=assigned_to&c%5B%5D=category&c%5B%5D=fixed_version&c%5B%5D=cf_7&group_by=&t%5B%5D=>`__
+`open issues for "Redirect Handling"
+<https://forge.typo3.org/projects/typo3cms-core/issues?utf8=✓&set_filter=1&f[]=category_id&op[category_id]==&v[category_id][]=1687&f[]=status_id&op[status_id]=o&f[]=&c[]=tracker&c[]=status&c[]=priority&c[]=subject&c[]=assigned_to&c[]=category&c[]=fixed_version&c[]=cf_7&group_by=&t[]=>`__