Revert "fix: add environment variable POSTGRES_USER (#20786)"

This reverts commit 83719cab73.

docker/.env.example

@@ -816,8 +816,6 @@ TEXT_GENERATION_TIMEOUT_MS=60000
 # ------------------------------
 
 PGUSER=${DB_USERNAME}
-# The name of the default postgres user.
-POSTGRES_USER=${DB_USERNAME}
 # The password for the default postgres user.
 POSTGRES_PASSWORD=${DB_PASSWORD}
 # The name of the default postgres database.

docker/docker-compose-template.yaml

@@ -85,7 +85,6 @@ services:
     restart: always
     environment:
       PGUSER: ${PGUSER:-postgres}
-      POSTGRES_USER: ${POSTGRES_USER:-postgres}
       POSTGRES_PASSWORD: ${POSTGRES_PASSWORD:-difyai123456}
       POSTGRES_DB: ${POSTGRES_DB:-dify}
       PGDATA: ${PGDATA:-/var/lib/postgresql/data/pgdata}

docker/docker-compose.yaml

@@ -357,7 +357,6 @@ x-shared-env: &shared-api-worker-env
   MAX_ITERATIONS_NUM: ${MAX_ITERATIONS_NUM:-99}
   TEXT_GENERATION_TIMEOUT_MS: ${TEXT_GENERATION_TIMEOUT_MS:-60000}
   PGUSER: ${PGUSER:-${DB_USERNAME}}
-  POSTGRES_USER: ${POSTGRES_USER:-${DB_USERNAME}}
   POSTGRES_PASSWORD: ${POSTGRES_PASSWORD:-${DB_PASSWORD}}
   POSTGRES_DB: ${POSTGRES_DB:-${DB_DATABASE}}
   PGDATA: ${PGDATA:-/var/lib/postgresql/data/pgdata}
@@ -593,7 +592,6 @@ services:
     restart: always
     environment:
       PGUSER: ${PGUSER:-postgres}
-      POSTGRES_USER: ${POSTGRES_USER:-postgres}
       POSTGRES_PASSWORD: ${POSTGRES_PASSWORD:-difyai123456}
       POSTGRES_DB: ${POSTGRES_DB:-dify}
       PGDATA: ${PGDATA:-/var/lib/postgresql/data/pgdata}