fix: add timeout for dde-shell services to prevent startup failure

Change the TimeoutStartSec from infinity to 10 seconds for both dde-
shell-plugin and dde-shell services. This prevents the deepin-service-
manager from getting stuck waiting indefinitely when these services fail
to start, allowing the system to properly handle startup failures and
improve overall system stability.

Log: Added startup timeout for dde-shell services

Influence:
1. Test normal startup of DDE desktop services
2. Verify services start within 10 seconds under normal conditions
3. Test startup delay scenarios to ensure timeout works correctly
4. Monitor deepin-service-manager startup behavior after timeout trigger
5. Verify system logs show proper timeout events
6. Test service restart behavior after timeout

fix: 为 dde-shell 服务添加超时机制以防止启动失败

将 dde-shell-plugin 和 dde-shell 服务的 TimeoutStartSec 从无限改为 10
秒。这可以防止 deepin-service-manager 在这些服务启动失败时无限期阻塞，使
系统能够正确处理启动失败，提升整体系统稳定性。

Log: 为 dde-shell 服务添加启动超时

Influence:
1. 测试 DDE 桌面服务的正常启动
2. 验证服务在正常条件下能在 10 秒内启动完成
3. 测试启动延迟场景以确保超时机制正确工作
4. 监控超时触发后 deepin-service-manager 的启动行为
5. 验证系统日志显示正确的超时事件
6. 测试超时后的服务重启行为

Author: 18202781743

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

@@ -18,7 +18,7 @@ After=dbus.socket
 Type=dbus
 BusName=com.deepin.dde.desktop
 ExecStart=/usr/bin/dde-shell -p %I
-TimeoutStartSec=infinity
+TimeoutStartSec=10s
 Slice=session.slice
 Restart=always
 RestartSec=1s

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

@@ -21,7 +21,7 @@ Wants=org.desktopspec.ApplicationManager1.service
 Type=dbus
 BusName=org.deepin.dde.Dock1
 ExecStart=/usr/bin/dde-shell -C %I --serviceName=org.deepin.dde.shell -d org.deepin.ds.desktop
-TimeoutStartSec=infinity
+TimeoutStartSec=10s
 Slice=session.slice
 Restart=always
 RestartSec=1s