terminal: restoreCursor is now longer fallible

We need to have sane behavior in error handling because the running
program that sends the restore cursor command has no way to realize it
failed. So if our style fails to add (our only fail case) then we revert
to no style.

https://ampcode.com/threads/T-019bd7dc-cf0b-7439-ad2f-218b3406277a

src/termio/stream_handler.zig

@@ -721,7 +721,7 @@ pub const StreamHandler = struct {
                 if (enabled) {
                     self.terminal.saveCursor();
                 } else {
-                    try self.terminal.restoreCursor();
+                    self.terminal.restoreCursor();
                 }
             },
 
@@ -933,7 +933,7 @@ pub const StreamHandler = struct {
     }
 
     pub inline fn restoreCursor(self: *StreamHandler) !void {
-        try self.terminal.restoreCursor();
+        self.terminal.restoreCursor();
     }
 
     pub fn enquiry(self: *StreamHandler) !void {