[UR][L0v2] Remove checkP2PAccess() from appendUSMMemcpy() (#22130)
The checkP2PAccess() helper in command_list_manager.cpp rejected
device-to-device USM memcpy operations between devices without P2P
access enabled, returning UR_RESULT_ERROR_INVALID_OPERATION.
Remove the check: P2P access controls memory residency (pinning), not
hardware data transfer. Level Zero can move data between devices via the
interconnect regardless of residency state, so blocking the copy at the
UR level is unnecessary and overly restrictive.
Update tests to match the new behavior.
Signed-off-by: Lukasz Dorau <lukasz.dorau@intel.com>
