Fix GitHub CI: use noble image + latest/noble xcat-dep

The xcat-dep APT repo now publishes only the noble (24.04) codename at
.../apt/latest/xcat-dep; the bionic/devel dist no longer exists, so
install_xcat failed on apt-get update/install. Run the workflow on
ubuntu-24.04 and point the apt source at latest/xcat-dep noble main.

Drop the apt-key step: apt-key is removed on Ubuntu 24.04 and the legacy
apt.key is gone from the xcat-dep dir; the repo already installs via
allow-insecure-repositories/allow-unauthenticated.

(cherry picked from commit 83323504a6)

.github/workflows/xcat_test.yml

@@ -2,7 +2,7 @@ name: xcat_test
 on: [pull_request, workflow_dispatch]
 jobs:
   xcat_pr_test:
-    runs-on: ubuntu-22.04
+    runs-on: ubuntu-24.04
     timeout-minutes: 60
     steps:
       - uses: actions/checkout@v6

github_action_xcat_test.pl

@@ -307,9 +307,8 @@ sub install_xcat{
 
     my @cmds = ("sudo ./mklocalrepo.sh",
                "sudo chmod 777 /etc/apt/sources.list",
-               "sudo echo \"deb [arch=amd64 allow-insecure=yes] http://xcat.org/files/xcat/repos/apt/devel/xcat-dep bionic main\" >> /etc/apt/sources.list",
-               "sudo echo \"deb [arch=ppc64el allow-insecure=yes] http://xcat.org/files/xcat/repos/apt/devel/xcat-dep bionic main\" >> /etc/apt/sources.list",
-               "sudo wget -q -O - \"http://xcat.org/files/xcat/repos/apt/apt.key\" | sudo apt-key add -",
+               "sudo echo \"deb [arch=amd64 allow-insecure=yes] http://xcat.org/files/xcat/repos/apt/latest/xcat-dep noble main\" >> /etc/apt/sources.list",
+               "sudo echo \"deb [arch=ppc64el allow-insecure=yes] http://xcat.org/files/xcat/repos/apt/latest/xcat-dep noble main\" >> /etc/apt/sources.list",
                "sudo apt-get -qq --allow-insecure-repositories update");
     chdir $ENV{RUNNER_WORKSPACE};;