[Issue#8479]Fix bug about the operator_cost error

tests/pytest/query/operator_cost.py

@@ -25,8 +25,7 @@ class TDTestCase:
         tdLog.debug("start to execute %s" % __file__)
         tdSql.init(conn.cursor(), logSql)
 
-        now = time.time()
-        self.ts = int(round(now * 1000))
+        self.ts = 1633333333000
         self.num = 10
 
     def run(self):
@@ -534,4 +533,4 @@ class TDTestCase:
 
 
 tdCases.addWindows(__file__, TDTestCase())
-tdCases.addLinux(__file__, TDTestCase())
\ No newline at end of file
+tdCases.addLinux(__file__, TDTestCase())