Via the Steam Store:

An update to Team Fortress 2 has been released. The update will be applied automatically when you restart Team Fortress 2. The major changes include:<br/> <ul style="padding-bottom: 0px; margin-bottom: 0px;" ><li>Ended the Jungle Inferno Campaign <li>Added a contracts-only pass to allow players who did not participate in the Jungle Inferno Campaign to access the Jungle Inferno contracts. This pass does not grant campaign-specific perks such as campaign case drops, enhanced rank badges, etc. </ul>