Add Ubuntu 26.04 to Vanagon builds

Author: bastelfreak

.github/workflows/build_vanagon.yml

@@ -77,6 +77,9 @@ jobs:
             'ubuntu-25.04-amd64'
             'ubuntu-25.04-aarch64'
             'ubuntu-25.04-armhf'
+            'ubuntu-25.04-amd64'
+            'ubuntu-25.04-aarch64'
+            'ubuntu-25.04-armhf'
             'windows-all-x64'
           )
           if [[ -n "${{ inputs.platform_list }}" ]]; then