[Bug] Unable to create really big caches

[jimsynz]

Observed Behaviour

I have a job which is trying to cache about 8GB of data rather than download it again from the internet. Sadly it fails with the following error:

level=error name=****** ts=2023-10-12T08:04:27.021698118Z caller=main.go:628 err="[IMPORTANT] build cache, rebuild failed, upload from <.nerves> to <bivouac_system_x86_64/eb0a191797624dd3a48fa681d3061212/.nerves>, rebuilder rebuild put file, upload file, pipe reader failed, storage backend put failure, put the object, MultipartUpload: upload multipart failed\n\tupload id: MWVmYTU1MzQtODY1YS00MjQ4LWEwMDItMWE5ODNkNTE5Yzg5LjQ1ODU0OTc2LWZhNzAtNDE5Mi05OTk0LThiNGZkY2EwMTViNw\ncaused by: RequestCanceled: request context canceled\ncaused by: context deadline exceeded\n"

See the entire job here: https://drone.harton.nz/bivouac/bivouac_system_x86_64/35/1/11

Steps to Reproduce

1. Generate a lot of data
2. Try and cache it.

Expected Behaviour

It should push the cache to the remote storage (even if it takes a long time).