fix: update systemd service configurations

1. Removed StartLimitBurst=3 from both dde-shell services as it was
unnecessary for desktop environment services
2. Changed restart policy from 'on-failure' to 'always' for dde-
shell@DDE.service to ensure continuous operation
3. These changes improve service reliability and simplify configuration
by removing redundant limits

fix: 更新 systemd 服务配置

1. 从两个 dde-shell 服务中移除了 StartLimitBurst=3 参数，因为对桌面环境
服务来说没有必要
2. 将 dde-shell@DDE.service 的重启策略从 'on-failure' 改为 'always' 以确
保持续运行
3. 这些改动通过移除冗余限制提高了服务可靠性并简化了配置

pms:BUG-321773

Author: 18202781743

systemd/dde-session-initialized.target.wants/dde-shell-plugin@org.deepin.ds.desktop.service

@@ -2,7 +2,6 @@
 Description=dde-shell for desktop
 RefuseManualStart=no
 RefuseManualStop=no
-StartLimitBurst=3
 CollectMode=inactive-or-failed
 
 Requisite=dde-session-pre.target

systemd/dde-session-initialized.target.wants/dde-shell@DDE.service

@@ -2,7 +2,6 @@
 Description=dde-shell for DDE service
 RefuseManualStart=no
 RefuseManualStop=no
-StartLimitBurst=3
 CollectMode=inactive-or-failed
 
 Requisite=dde-session-pre.target
@@ -32,5 +31,5 @@ Type=simple
 ExecStart=/usr/bin/dde-shell -C %I --serviceName=org.deepin.dde.shell -d org.deepin.ds.desktop
 TimeoutStartSec=infinity
 Slice=session.slice
-Restart=on-failure
+Restart=always
 RestartSec=1s