fixes#25626
This pull request introduces a small change to the `mapIt` template in
`sequtils.nim`. The update adds the `used` pragma to the injected `it`
variable, which can help suppress unused variable warnings in certain
cases.
- Added the `used` pragma to the injected `it` variable in the `mapIt`
template to prevent unused variable warnings.
or it should give a better warning or something if `it` is not used
(cherry picked from commit fb6fa96979)
48bb08ea92