fix(deps): update flyway to v11.20.0

Author: renovate[bot]

backend/pom.xml

@@ -63,12 +63,12 @@
         <dependency>
             <groupId>org.flywaydb</groupId>
             <artifactId>flyway-core</artifactId>
-            <version>11.11.1</version>
+            <version>11.20.0</version>
         </dependency>
         <dependency>
             <groupId>org.flywaydb</groupId>
             <artifactId>flyway-database-postgresql</artifactId>
-            <version>11.11.1</version>
+            <version>11.20.0</version>
             <scope>runtime</scope>
         </dependency>
         <dependency>