[NFC][UR][L0] Eliminate code duplication in kernel launch logic (#19562)
This PR removes duplicated code between regular and cooperative kernel
launches. The only actual difference between these paths is the use of
either `zeCommandListAppendLaunchKernel` or
`zeCommandListAppendLaunchCooperativeKernel`.
This simplifies maintenance by consolidating identical code and reduces
the risk of divergence.