Tests requiring autoAnalyze disabled should assert it is disabled

## Enhancement

Forked from https://github.com/pingcap/tidb/pull/34643

In the tests that require AutoAnalyze disabled, we should potentially assert that it is infact disabled. i.e.
```
require.Equal(variable.RunAutoAnalyze.Load(), false)
```

Another potential fix is to make setting atomics outside of system variables more stable. Currently changes are reverted when the SetGlobal func is called in the sysvar cache.