Revert "XWIKI-11348: Flamingo Theme preview is broken (on view mode) when "lessCode" is filled."

This reverts commit 00a70535d5943296a95cd515bc84f1fbec36d4f2.
XWIKI-11349: The 'lessCode' variable is not taken into account.

(cherry picked from commit 7d562778b138bd4aa2b7b2988290164ee750a05e)