ext-image-copy-capture-v1: Fix typo in ext_image_copy_capture_frame_v1::destroy

Signed-off-by: Tranquil Ity <tranquillitycodes@proton.me>
Closes: #217

staging/ext-image-copy-capture/ext-image-copy-capture-v1.xml

@@ -221,7 +221,7 @@
 
     <request name="destroy" type="destructor">
       <description summary="destroy this object">
-        Destroys the session. This request can be sent at any time by the
+        Destroys the frame. This request can be sent at any time by the
         client.
       </description>
     </request>