ci: stop overriding POSTGRES_HOST in test helpers

backend/db/db_test_init.go

@@ -11,14 +11,8 @@ import (
 
 func init() {
 	// Set defaults for test environment if not already set
-	host := os.Getenv("POSTGRES_HOST")
-	if host == "" {
-		if h := os.Getenv("TEST_DB_HOST"); h != "" {
-			host = h
-		} else {
-			host = "localhost"
-		}
-		os.Setenv("POSTGRES_HOST", host)
+	if os.Getenv("POSTGRES_HOST") == "" {
+		os.Setenv("POSTGRES_HOST", "localhost")
 	}
 	if os.Getenv("POSTGRES_USER") == "" {
 		os.Setenv("POSTGRES_USER", "myuser")