style(yaml): apply ansible-lint 26.10.1 autofix

A freshly built dev container installs ansible-lint unpinned (26.10.1,
yamllint 1.38.0), and its --fix pass in make autoformat now drops the
trailing blank line of meta/packages.yml and
roles/sys-svc-container/meta/packages.yml and adds the missing document
start to roles/svc-net-wireguard/files/test/compose.yml (from #323).
Parsed YAML is unchanged.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

meta/packages.yml

@@ -317,4 +317,3 @@ wireshark-gui:
     - wireshark
   RedHat:
     - wireshark
-

roles/svc-net-wireguard/files/test/compose.yml

@@ -1,3 +1,4 @@
+---
 x-host: &host
   command: ["sleep", "infinity"]
   cap_add:

roles/sys-svc-container/meta/packages.yml

@@ -22,4 +22,3 @@ docker-cli:
       - docker-compose-plugin
     repo:
       managed_externally: sys-svc-container configures the download.docker.com repository per distro before installing
-