[Tei-council] Freeze for TEI Release 4.9.0

Dear Council, As we are releasing TEI version 4.9.0 and the Stylesheets version 7.58.0, please do not commit anything to the following branches: tei:dev, tei:release-4.9.0, tei:released, stylesheets:dev, stylesheets:release-7.58.0, stylesheets:released. We will send a follow up notice once the release is complete. Best, Raff