Consider refactoring blobfs to use new gocloud.dev io.FS support

[hairyhenderson]

          > all: Make blob.Bucket implement io/fs.FS and io/fs.SubFS.

this is super interesting... I'm going to consider refactoring to use this 🤔

Originally posted by @hairyhenderson in #379 (comment)

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This issue is stale because it has been open for 60 days with no activity. Remove stale label or comment or this will be automatically closed in a few days.

[github-actions]

This issue is stale because it has been open for 60 days with no activity. Remove stale label or comment or this will be automatically closed in a few days.