drm/xe: Always capture exec queues on snapshot

Always capture exec queues on snapshot regardless if exec queue has
pending jobs or not. Having jobs or not does indicate whether the exec
queue capture is useful.

Example bugs that would not be easily detected by skipping capture when
pending job list is empty:
- Jobs pending on exec queue have dependencies
- Leaking exec queue refs
- GuC protocol issues (i.e. losing G2H)

In addition to above bugs, in general it just useful to see every exec
queue registered with the GuC and its state.

Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Matthew Brost <matthew.brost@intel.com>
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240405211632.223568-2-matthew.brost@intel.com