updated postgres image to from 12 to 15 version

application/src/main/data/json/edge/install_instructions/docker/instructions.md

@@ -51,7 +51,7 @@ services:
       - ~/.mytb-edge-logs:/var/log/tb-edge
   postgres:
     restart: always
-    image: "postgres:12"
+    image: "postgres:15"
     ports:
       - "5432"
     environment:

docker/docker-compose.hybrid.yml

@@ -19,7 +19,7 @@ version: '3.0'
 services:
   postgres:
     restart: always
-    image: "postgres:12"
+    image: "postgres:15"
     ports:
       - "5432"
     environment:

docker/docker-compose.postgres.yml

@@ -19,7 +19,7 @@ version: '3.0'
 services:
   postgres:
     restart: always
-    image: "postgres:12"
+    image: "postgres:15"
     ports:
     - "5432"
     environment: