task: set io.status=DONE on emcIoAbort to unblock tool-change abort

After commit 764655e moved IO handling from the out-of-process
iocontrol into Task, EMC_TOOL_ABORT no longer flips emcioStatus.status
back to RCS_DONE. The old NML dispatcher set RCS_DONE by default for
every command; the new in-process emcIoAbort cleared the tool_change
and tool_prepare pins but left status stuck at RCS_EXEC from the prior
emcToolLoad/emcToolPrepare call.

emctaskmain's MDI, auto and state-restore paths gate on
io.status == RCS_DONE, so an abort received while tool-change was
pending wedged the UI and prevented further MDI or program runs.

Closes #3675

Author: grandixximo

src/emc/task/taskclass.cc

@@ -369,6 +369,9 @@ int Task::emcIoAbort(EMC_ABORT /*reason*/)//EMC_TOOL_ABORT_TYPE
     iocontrol_data.coolant_flood = 0;                /* coolant flood output pin */
     iocontrol_data.tool_change = 0;                /* abort tool change if in progress */
     iocontrol_data.tool_prepare = 0;                /* abort tool prepare if in progress */
+    // release task wait on pending tool-change/prepare (old NML iocontrol
+    // returned RCS_DONE by default; in-process call must do it explicitly)
+    emcioStatus.status = RCS_STATUS::DONE;
     return 0;
 }