Clean-up runtimes management in runtime_service

[tomaka]

Fix #2467

We now clean up old runtimes when it makes sense, rather than after a download where it doesn't make sense.

[mergify]

Automatically approving tomaka's pull requests. This auto-approval will be removed once more maintainers are active.

[tomaka]

This was the main bug behind #2467

[github-actions]

twiggy diff report

Difference in .wasm size before and after this pull request.

---

 Delta Bytes │ Item
─────────────┼─────────────────────────────────────────────────────────────────────────────────────────────────────────────────
        -682 ┊ <slab::Slab<T> as core::iter::traits::collect::FromIterator<(usize,T)>>::from_iter::h05085178e898dc6e
        +682 ┊ <slab::Slab<T> as core::iter::traits::collect::FromIterator<(usize,T)>>::from_iter::h5e213dc6691e074f
        +417 ┊ core::ops::function::impls::<impl core::ops::function::FnOnce<A> for &mut F>::call_once::h0094c084a347f4ca
        -417 ┊ core::ops::function::impls::<impl core::ops::function::FnOnce<A> for &mut F>::call_once::hee2698b57d200a4c
        +293 ┊ <alloc::vec::Vec<T> as alloc::vec::spec_from_iter_nested::SpecFromIterNested<T,I>>::from_iter::h17704046b04e9b9c
        -293 ┊ <alloc::vec::Vec<T> as alloc::vec::spec_from_iter_nested::SpecFromIterNested<T,I>>::from_iter::h41448ea2b94498d1
        +293 ┊ <alloc::vec::Vec<T> as alloc::vec::spec_from_iter_nested::SpecFromIterNested<T,I>>::from_iter::h6faaf639621b42ae
        -293 ┊ <alloc::vec::Vec<T> as alloc::vec::spec_from_iter_nested::SpecFromIterNested<T,I>>::from_iter::h82df4da3915cf2d3
        -293 ┊ <alloc::vec::Vec<T> as alloc::vec::spec_from_iter_nested::SpecFromIterNested<T,I>>::from_iter::ha10589a8b47bc38d
        +293 ┊ <alloc::vec::Vec<T> as alloc::vec::spec_from_iter_nested::SpecFromIterNested<T,I>>::from_iter::hb506c76ad1abe76a
        +200 ┊ smoldot::chain::async_tree::AsyncTree<TNow,TBl,TAsync>::map_async_op_user_data::h433803251b98303c
        -200 ┊ smoldot::chain::async_tree::AsyncTree<TNow,TBl,TAsync>::map_async_op_user_data::hbe00395cc4b9afe0
        -184 ┊ alloc::vec::Vec<T,A>::extend_desugared::h398c45e2da060f39
        +184 ┊ alloc::vec::Vec<T,A>::extend_desugared::h60ef2608e6fbcd55
        -184 ┊ alloc::vec::Vec<T,A>::extend_desugared::h9204ec0bf66040f4
        -184 ┊ alloc::vec::Vec<T,A>::extend_desugared::h9e03642c1ae124f7
        +184 ┊ alloc::vec::Vec<T,A>::extend_desugared::ha0437ef903ee859c
        +184 ┊ alloc::vec::Vec<T,A>::extend_desugared::he3cce62a76f46275
        +154 ┊ slab::Slab<T>::retain::hc5d9eb9a250dc2b3
        -154 ┊ slab::Slab<T>::retain::hcdf5a293f6155417
          -1 ┊ ... and 31 more.
          -1 ┊ Σ [51 Total Rows]

[melekes]

👍