Remove deprecated SchemaManager methods

UPGRADE.md

 # Upgrade to 3.0
 
+## BC BREAK: Changes in the `Doctrine\DBAL\Schema` API
+
+- Removed unused method `Doctrine\DBAL\Schema\AbstractSchemaManager::_getPortableFunctionsList()`
+- Removed unused method `Doctrine\DBAL\Schema\AbstractSchemaManager::_getPortableFunctionDefinition()`
+- Removed unused method `Doctrine\DBAL\Schema\OracleSchemaManager::_getPortableFunctionDefinition()`
+- Removed unused method `Doctrine\DBAL\Schema\SqliteSchemaManager::_getPortableTableIndexDefinition()`
+
 ## BC BREAK: Removed support for DB-generated UUIDs
 
 The support for DB-generated UUIDs was removed as non-portable.

src/Schema/AbstractSchemaManager.php

@@ -668,41 +668,6 @@ abstract class AbstractSchemaManager
         return $namespace;
     }
 
-    /**
-     * @deprecated
-     *
-     * @param mixed[][] $functions
-     *
-     * @return mixed[][]
-     */
-    protected function _getPortableFunctionsList($functions)
-    {
-        $list = [];
-        foreach ($functions as $value) {
-            $value = $this->_getPortableFunctionDefinition($value);
-
-            if (! $value) {
-                continue;
-            }
-
-            $list[] = $value;
-        }
-
-        return $list;
-    }
-
-    /**
-     * @deprecated
-     *
-     * @param mixed[] $function
-     *
-     * @return mixed
-     */
-    protected function _getPortableFunctionDefinition($function)
-    {
-        return $function;
-    }
-
     /**
      * @param mixed[][] $triggers
      *

src/Schema/OracleSchemaManager.php

@@ -267,18 +267,6 @@ class OracleSchemaManager extends AbstractSchemaManager
         );
     }
 
-    /**
-     * {@inheritdoc}
-     *
-     * @deprecated
-     */
-    protected function _getPortableFunctionDefinition($function)
-    {
-        $function = array_change_key_case($function, CASE_LOWER);
-
-        return $function['name'];
-    }
-
     /**
      * {@inheritdoc}
      */

src/Schema/SqliteSchemaManager.php

@@ -224,21 +224,6 @@ class SqliteSchemaManager extends AbstractSchemaManager
         return parent::_getPortableTableIndexesList($indexBuffer, $tableName);
     }
 
-    /**
-     * @deprecated
-     *
-     * @param array<string, mixed> $tableIndex
-     *
-     * @return array<string, bool|string>
-     */
-    protected function _getPortableTableIndexDefinition($tableIndex)
-    {
-        return [
-            'name' => $tableIndex['name'],
-            'unique' => (bool) $tableIndex['unique'],
-        ];
-    }
-
     /**
      * {@inheritdoc}
      */