nix: no SUPERUSER for connection role

Change :USER to :PGUSER in SQL scripts

test/io/fixtures.sql

@@ -4,7 +4,7 @@
 set search_path to public;
 
 CREATE ROLE postgrest_test_anonymous;
-ALTER ROLE :USER SET pgrst.db_anon_role = 'postgrest_test_anonymous';
+ALTER ROLE :PGUSER SET pgrst.db_anon_role = 'postgrest_test_anonymous';
 
 CREATE ROLE postgrest_test_author;
 
@@ -14,7 +14,7 @@ alter role postgrest_test_serializable set default_transaction_isolation = 'seri
 CREATE ROLE postgrest_test_repeatable_read;
 alter role postgrest_test_repeatable_read set default_transaction_isolation = 'REPEATABLE READ';
 
-GRANT postgrest_test_anonymous, postgrest_test_author, postgrest_test_serializable, postgrest_test_repeatable_read TO :USER;
+GRANT postgrest_test_anonymous, postgrest_test_author, postgrest_test_serializable, postgrest_test_repeatable_read TO :PGUSER;
 
 CREATE SCHEMA v1;
 GRANT USAGE ON SCHEMA v1 TO postgrest_test_anonymous;

test/load/fixtures.sql

@@ -1,5 +1,5 @@
 CREATE ROLE postgrest_test_anonymous;
-GRANT postgrest_test_anonymous TO :USER;
+GRANT postgrest_test_anonymous TO :PGUSER;
 CREATE SCHEMA test;
 
 -- PUT+PATCH target needs one record and column to modify

test/spec/SpecHelper.hs

@@ -211,7 +211,7 @@ testObservabilityCfg = baseCfg { configServerTraceHeader = Just $ mk "X-Request-
 
 analyzeTable :: Text -> IO ()
 analyzeTable tableName =
-  void $ readProcess "psql" ["--set", "ON_ERROR_STOP=1", "-a", "-c", toS $ "ANALYZE test.\"" <> tableName <> "\""] []
+  void $ readProcess "psql" ["-U", "postgres", "--set", "ON_ERROR_STOP=1", "-a", "-c", toS $ "ANALYZE test.\"" <> tableName <> "\""] []
 
 rangeHdrs :: ByteRange -> [Header]
 rangeHdrs r = [rangeUnit, (hRange, renderByteRange r)]

test/spec/fixtures/roles.sql

@@ -1,7 +1,6 @@
-\set AUTHENTICATOR current_user
 DROP ROLE IF EXISTS postgrest_test_anonymous, postgrest_test_default_role, postgrest_test_author;
 CREATE ROLE postgrest_test_anonymous;
 CREATE ROLE postgrest_test_default_role;
 CREATE ROLE postgrest_test_author;
 
-GRANT postgrest_test_anonymous, postgrest_test_default_role, postgrest_test_author TO :USER;
+GRANT postgrest_test_anonymous, postgrest_test_default_role, postgrest_test_author TO :PGUSER;