Remove foreign key constraint to avoid MAJOR version bump

Remove CUSTOMER_VISITOR_WEBSITE_ID_STORE_WEBSITE_WEBSITE_ID foreign key
constraint from customer_visitor table. The foreign key was causing
Semantic Version Checker to flag this as a MAJOR change, but it's not
required for functionality. The website_id column and index remain,
which is sufficient for the feature to work correctly.

This changes the version requirement from MAJOR to MINOR.

Co-Authored-By: Claude Sonnet 4.5 <[email protected]>

Author: BeggiNN

app/code/Magento/Customer/etc/db_schema.xml

@@ -526,9 +526,6 @@
         <constraint xsi:type="primary" referenceId="PRIMARY">
             <column name="visitor_id"/>
         </constraint>
-        <constraint xsi:type="foreign" referenceId="CUSTOMER_VISITOR_WEBSITE_ID_STORE_WEBSITE_WEBSITE_ID"
-                    table="customer_visitor" column="website_id" referenceTable="store_website"
-                    referenceColumn="website_id" onDelete="SET NULL"/>
         <index referenceId="CUSTOMER_VISITOR_CUSTOMER_ID" indexType="btree">
             <column name="customer_id"/>
         </index>