fix: resolve nameless TableForeign on drop foreign key (typeorm#9460)

Closes typeorm#9432

Author: iJhefe

src/driver/postgres/PostgresQueryRunner.ts

@@ -2874,6 +2874,15 @@ export class PostgresQueryRunner
                 `Supplied foreign key was not found in table ${table.name}`,
             )
 
+        if (!foreignKey.name) {
+            foreignKey.name = this.connection.namingStrategy.foreignKeyName(
+                table,
+                foreignKey.columnNames,
+                this.getTablePath(foreignKey),
+                foreignKey.referencedColumnNames,
+            )
+        }
+
         const up = this.dropForeignKeySql(table, foreignKey)
         const down = this.createForeignKeySql(table, foreignKey)
         await this.executeQueries(up, down)