Update postgres Docker tag from 14.5 to v15 (docker-compose.yml) (#6994)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

docker-compose.yml

@@ -143,7 +143,7 @@ services:
     volumes:
       - defectdojo_data:/var/lib/mysql
   postgres:
-    image: postgres:14.5-alpine@sha256:ac09c433f64f2d310a83e5cc24dadc13561f645199d4ec8e503824de22e14668
+    image: postgres:15.0-alpine@sha256:09d57b502063c77d8896683ff5126187025d7b2e2b4378a896b90dced36bc083
     profiles: 
       - postgres-rabbitmq
       - postgres-redis