fix: update umami tag to v3.0.3 (#2072)

Author: spaenleh

.devcontainer/docker-compose.yml

@@ -1,5 +1,3 @@
-version: '3'
-
 services:
   core:
     hostname: core
@@ -116,7 +114,7 @@ services:
 
   umami:
     hostname: umami
-    image: ghcr.io/umami-software/umami:postgresql-latest
+    image: ghcr.io/umami-software/umami:3.0.3
     environment:
       DATABASE_URL: postgresql://umami:umami@db:5432/umami
       DATABASE_TYPE: postgresql