`ScannerContext` will schedule scanners even after stopped, and confused with `_is_finished` and `_should_stop`. Only Fix the concurrency bugs when scanner is stopped or finished reported in https://github.com/apache/doris/pull/28384
`ScannerContext` will schedule scanners even after stopped, and confused with `_is_finished` and `_should_stop`. Only Fix the concurrency bugs when scanner is stopped or finished reported in https://github.com/apache/doris/pull/28384