use par_for_each_in in par_body_owners and collect_crate_mono_items

[SparrowLii]

Using par_iter in non-parallel mode will cause the entire process to abort when any iteration panics. So we can use par_for_each_in instead to make the error message consistent with parallel mode. This means that the compiler will output more error messages in some cases. This fixes the following ui tests when set parallel-compiler = true:

    [ui] src/test\ui\privacy\privacy2.rs
    [ui] src/test\ui\privacy\privacy3.rs
    [ui] src/test\ui\type_length_limit.rs

This refers to #68171

Updates #75760