find-unneeded-includes: don't propose debug/bitset either

Found while checking include/vcl/fontcapabilities.hxx

Change-Id: Ib598978672d08d3cae7bf6f96d1b874ca13fcb5f
Reviewed-on: https://gerrit.libreoffice.org/66254
Tested-by: Jenkins
Reviewed-by: Miklos Vajna <vmiklos@collabora.com>

bin/find-unneeded-includes

@@ -41,6 +41,7 @@ def ignoreRemoval(include, toAdd, absFileName, moduleRules):
     # Avoid debug STL.
     debugStl = {
         "array": "debug/array",
+        "bitset": "debug/bitset",
         "deque": "debug/deque",
         "list": "debug/list",
         "map": "debug/map.h",