[BugFix] fix Duplicate key exception when get table statistics

[kaijianding]

Why I'm doing:

CREATE TABLE `ptbl5` (
  `dt` date NULL COMMENT "",
  `id` int(11) NULL COMMENT "",
  `name` varchar(65533) NULL COMMENT ""
) ENGINE=OLAP
DUPLICATE KEY(`dt`, `id`, `name`)
PARTITION BY RANGE(`dt`)
(PARTITION p20250428 VALUES [("2025-04-28"), ("2025-04-29")),
PARTITION p20250429 VALUES [("2025-04-29"), ("2025-04-30")))
DISTRIBUTED BY HASH(`id`, `name`)
PROPERTIES (
"compression" = "LZ4",
"fast_schema_evolution" = "true",
"replicated_storage" = "true",
"replication_num" = "1"
);

insert into ptbl5 values("2025-04-29",1,'a');

-- ERROR 1064 (HY000): Duplicate key 5031178 (attempted merging values Optional.empty and Optional.empty)
select min(dt),max(dt) from ptbl5;

What I'm doing:

Fixes #issue

What type of PR is this:

• [x] BugFix
• [ ] Feature
• [ ] Enhancement
• [ ] Refactor
• [ ] UT
• [ ] Doc
• [ ] Tool

Does this PR entail a change in behavior?

• [ ] Yes, this PR will result in a change in behavior.
• [x] No, this PR will not result in a change in behavior.

Bugfix cherry-pick branch check:

• [x] I have checked the version labels which the pr will be auto-backported to the target branch
  • [x] 3.5
  • [x] 3.4
  • [x] 3.3

[sonarqubecloud[bot]]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[kangkaisen]

please add test cases for it

[github-actions[bot]]

[Java-Extensions Incremental Coverage Report]

:white_check_mark: pass : 0 / 0 (0%)

[github-actions[bot]]

[FE Incremental Coverage Report]

:white_check_mark: pass : 5 / 5 (100.00%)

file detail

	path	covered_line	new_line	coverage	not_covered_line_detail
:large_blue_circle:	com/starrocks/sql/optimizer/statistics/CachedStatisticStorage.java	5	5	100.00%	[]

[github-actions[bot]]

[BE Incremental Coverage Report]

:white_check_mark: pass : 0 / 0 (0%)

[kevincai]

This PR is replaced by #60162 , close this one for now.