ci: respect TEST_DB_HOST in db package tests

backend/db/db_test.go

@@ -12,9 +12,13 @@ import (
 )
 
 func resetEnv() {
+	host := "localhost"
+	if h := os.Getenv("TEST_DB_HOST"); h != "" {
+		host = h
+	}
 	os.Setenv("POSTGRES_USER", "myuser")
 	os.Setenv("POSTGRES_PASSWORD", "mypassword")
-	os.Setenv("POSTGRES_HOST", "localhost")
+	os.Setenv("POSTGRES_HOST", host)
 	os.Setenv("POSTGRES_DB", "crussell_test_db")
 }