Update Q2 print height (#10843)

* The 0.30mm layer height configuration for the 0.4 nozzle of the QIDI model has been removed

* Revert "The 0.30mm layer height configuration for the 0.4 nozzle of the QIDI model has been removed"

This reverts commit 8d296720b8de58b1bfa4f008a24cee841a8472c6.

* Update Qidi Q2 0.4 nozzle.json

修改Q2打印高度

---------

Co-authored-by: SoftFever <softfeverever@gmail.com>

resources/profiles/Qidi/machine/Qidi Q2 0.4 nozzle.json

@@ -57,7 +57,7 @@
         "270x270",
         "0x270"
     ],
-    "printable_height": "260",
+    "printable_height": "256",
     "retract_lift_below": [
         "259"
     ],
@@ -66,4 +66,4 @@
     "thumbnail_size": [
         "50x50"
     ]
-}
+}