Docs: Reorder 4.6.22 Discounts update section and remove dedicated file

Author: mnocon

docs/update_and_migration/from_4.6/update_from_4.6.md

@@ -395,26 +395,6 @@ To use the [latest features](ibexa_dxp_v4.6.md) added to them, update them separ
 
     Then apply manually the changes described below.
 
-    ## 4.6.22
-
-    ### Database update
-
-    Run the following scripts:
-
-    === "MySQL"
-
-        ``` sql
-        alter table ibexa_discount add override_prioritization tinyint(1) not null default 0;
-        create index ibexa_discount_prioritization_idx on ibexa_discount (override_prioritization, type, priority);
-        ```
-
-    === "PostgreSQL"
-
-        ``` sql
-        alter table ibexa_discount add override_prioritization boolean not null default false;
-        create index ibexa_discount_prioritization_idx on ibexa_discount (override_prioritization, type, priority);
-        ```
-
     ## 4.6.20
 
     ### Policy changes
@@ -546,6 +526,26 @@ To use the [latest features](ibexa_dxp_v4.6.md) added to them, update them separ
                 REFERENCES ezuser (contentobject_id) ON UPDATE CASCADE ON DELETE CASCADE NOT DEFERRABLE INITIALLY IMMEDIATE;
         ```
 
+    ## 4.6.22
+
+    ### Database update
+
+    Run the following scripts:
+
+    === "MySQL"
+
+        ``` sql
+        alter table ibexa_discount add override_prioritization tinyint(1) not null default 0;
+        create index ibexa_discount_prioritization_idx on ibexa_discount (override_prioritization, type, priority);
+        ```
+
+    === "PostgreSQL"
+
+        ``` sql
+        alter table ibexa_discount add override_prioritization boolean not null default false;
+        create index ibexa_discount_prioritization_idx on ibexa_discount (override_prioritization, type, priority);
+        ```
+
 === "AI actions"
 
     Run the following command to get the latest version: