Update OMShell License (#15452)* Updated to OSMC-PL 1.8 Header * AGPL 3 + OSMC-PL 1.8 * Checked 17 files, skipped 2 (excluded), 0 failures, 17 fixed.* Added `*/omc_config*.h.in` glob to exception list (build-generated config headers).* Added `OMShell` to CI license check workflow.