netlab 26.06: OSPFv3 on FortiOS, MPLS/VPN on SR Linux

netlab release 26.06 adds OSPFv3 support on FortiOS (by @a-v-popov ) and MPLS/VPN support on SR Linux. We also ensured the installation scripts work on Ubuntu 26.04 (everything else was OK) and updated the installed Vagrant version to 2.4.9 (we&rsquo;re not using new Vagrant features; you don&rsquo;t have to upgrade it in an existing installation). Other than that, we added a few improvements and…