many undeleted files in /tmp

**Bug Description**

generally, if a test fails, cleanup may not executed in the test end. like
https://github.com/4paradigm/openmldb/blob/8142820cc51bcd01a276bb8b40b2d241dd624419/src/nameserver/name_server_test.cc#L579

files in `/tmp` got cleanup by strategy, however, they may produce many useless files in a short time

**Expected Behavior**

**Steps to Reproduce**

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The issue points to a specific test file, src/nameserver/name_server_test.cc at line 579, where cleanup may not execute on test failure. Start by examining that test and similar tests to understand the temporary file creation pattern. Run the test suite to reproduce the issue and see which files are left in /tmp. Determine how to ensure cleanup happens even on failure, possibly using RAII or try-catch blocks.

Scritto dal modello di indicizzazione a partire dal testo della issue.