new release: ocaml-solo5 0.8.2

[hannesm]

• malloc: fix the memory allocation tracking to be precise (fixes On hvt, I sometimes get a negative reading from malloc_memory_usage mirage/ocaml-solo5#126 reported by @hannesm, Fix used memory estimation  mirage/ocaml-solo5#127 @palainp)

[hannesm]

The lint failures: indeed, there's a dune-project file in the repository (I'm not sure why). But the entire project does not depend on dune. (The dune-project file is helpful for CI of the examples).

The lower-bound failures: some solo5 releases contain -Werror and that fails with more modern C compilers. Nothing I can do about it (in this PR).

[hannesm]

so, after the CI run -- this is fine to be merged.

[avsm]

Thanks for the triage! Looks good to merge.