Package and deploy dulwich 0.20.43 in production

Latest dulwich release (0.20.43) finally drops caching of responses when using the HTTP client (I helped debugging the last remaining issue, see commit).

Current dulwich version we are using in production caches HTTP responses twice in memory which can be problematic when receiving a large packfile.

So we should upgrade dulwich in production to increase git loader performance in terms of CPU and memory usage.

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Migrated from T4311 (view on Phabricator)