fdo#63154 Remove unused solar.h reference in editeng

Change-Id: I472cb0dcfcb2d36fab65041acb47bd75d22a7b3f
Reviewed-on: https://gerrit.libreoffice.org/8119
Reviewed-by: Caolán McNamara <caolanm@redhat.com>
Tested-by: Caolán McNamara <caolanm@redhat.com>