[bug](udf) fix udf return type of decimal check scale must is 9

[zhangstar333]

Proposed changes

ERROR 1105 (HY000): errCode = 2, detailMessage = [INTERNAL_ERROR]UdfRuntimeException: UDF::evaluate() ran into a problem. CAUSED BY: IllegalArgumentException: Scale of DECIMALV2 must be 9
Issue Number: close #xxx

Problem summary

Describe your changes.

Checklist(Required)

1. Does it affect the original behavior:
   • Yes
   • No
   • I don't know
2. Has unit tests been added:
   • Yes
   • No
   • No Need
3. Has document been added or modified:
   • Yes
   • No
   • No Need
4. Does it need to update dependencies:
   • Yes
   • No
5. Are there any changes that cannot be rolled back:
   • Yes (If Yes, please explain WHY)
   • No

Further comments

If this is a relatively large or complex change, kick off the discussion at dev@doris.apache.org by explaining why you chose the solution you did and what alternatives you considered, etc...

[carlvinhust2012]

What is the effect of this change? Not report error？

[hello-stephen]

TeamCity pipeline, clickbench performance test result:
the sum of best hot time: 34.3 seconds
stream load tsv: 463 seconds loaded 74807831229 Bytes, about 154 MB/s
stream load json: 37 seconds loaded 2358488459 Bytes, about 60 MB/s
stream load orc: 68 seconds loaded 1101869774 Bytes, about 15 MB/s
https://doris-community-test-1308700295.cos.ap-hongkong.myqcloud.com/tmp/20230210162142_clickbench_pr_93954.html

[zhangstar333]

What is the effect of this change? Not report error？

remove the check, and set scale to 9 always

[yiguolei]

Add some regression test for this?

[HappenLee]

LGTM