ui: remove max value (8) of maxsnaps because it might be greater than 8 (#7066)

Fixes #7051

The value of "Keep" when create snapshot policy was automatically reset to 8 if the input is greater than 8.
However, the max value of recurring snapshots is determined by global settings snapshot.max.daily / snapshot.max.hourly / snapshot.max.monthly / snapshot.max.weekly, which is 8 by default, but users can input other values greater than 8.
This PR removes this restriction on UI and cloudsack management server will check if the value is valid.

Author: weizhouapache

ui/src/views/storage/FormSchedule.vue

@@ -117,8 +117,7 @@
                   <a-input-number
                     style="width: 100%"
                     v-model:value="form.maxsnaps"
-                    :min="1"
-                    :max="8" />
+                    :min="1" />
                 </a-tooltip>
               </a-form-item>
             </a-col>