[SYCL] Avoid redundant global timestamp query for profiling tag events (#22810)
Specification change: https://github.com/intel/llvm/pull/22847
`submit_profiling_tag` and `enqueue_signal_event` already record a
GPU-written global timestamp via
`zeCommandListAppendWriteGlobalTimestamp`. The additional
`urDeviceGetGlobalTimestamps` call used to capture the submission and
start times adds no value, since users only rely on the end timestamp.
Change implementation so that a tag event carries a single timestamp,
reported alike for `command_submit`, `command_start` and `command_end`.
Assisted-By: Claude