[BUG] Fix colocate join memory limit problem (#4894)

[wyndia]

Proposed changes

In colocate join, the memory limit of each instance is usually less than the value of exec_mem_limit, which could lead to query failure (Memory exceed limit).
Since the purpose of resetting colocate-join memory limit (/fe/fe-core/src/main/java/org/apache/doris/qe/Coordinator.java) is unclear to me, I just change the default value of query_colocate_join_memory_limit_penalty_factor from 8 to 1, as a hotfix.

Types of changes

• Bugfix (non-breaking change which fixes an issue)
• [] New feature (non-breaking change which adds functionality)
• [] Breaking change (fix or feature that would cause existing functionality to not work as expected)
• [] Documentation Update (if none of the other choices apply)
• [] Code refactor (Modify the code structure, format the code, etc...)

Checklist

• I have create an issue on (Fix Colocate Join时部分Instance的可用内存与exec_mem_limit参数不一致 #4894 ), and have described the bug/feature there in detail
• [] Compiling and unit tests pass locally with my changes
• [] I have added tests that prove my fix is effective or that my feature works
• [] If this change need a document change, I have updated the document
• [] Any dependent changes have been merged

[EmmyMiao87]

LGTM