ci: support ubuntu 26.04

Author: sergiud

.github/workflows/linux.yml

@@ -18,6 +18,7 @@ jobs:
         os:
           - ubuntu-22.04
           - ubuntu-24.04
+          - ubuntu-26.04
         build_type: [Release, Debug]
         lib: [shared, static]
         components: [minimal, lgpl, gpl]