and make cppu::OTypeCollection::getTypes be const

Change-Id: I2dd1c0bacb2e1872f8b7a0da72f73013b04bef3c
Reviewed-on: https://gerrit.libreoffice.org/68536
Tested-by: Jenkins
Reviewed-by: Noel Grandin <noel.grandin@collabora.co.uk>