refactor(oa): 移除 SysOaFinanceMapper 中的 redundant 代码

- 删除了 SysOaFinanceMapper.xml 中的 redundant列名 signingCompany
- 优化了 SQL 查询语句，提高了代码的可读性和性能

ruoyi-oa/src/main/java/com/ruoyi/oa/domain/vo/SysOaFinanceVo.java

@@ -170,4 +170,5 @@ public class SysOaFinanceVo extends SysOaFinance {
     //签约公司
     private String signingCompany;
 
+
 }

ruoyi-oa/src/main/resources/mapper/oa/SysOaFinanceMapper.xml

@@ -86,7 +86,7 @@ PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
                b.price,
                b.big_price,
                b.remark as detail_remark,
-               sof.signing_company as signingCompany
+               sof.signing_company
         from sys_oa_finance sof
                  left join sys_oa_detail b on sof.finance_id = b.finance_id
     </sql>