Use published bootc-internal-{utils,blockdev} crates

[cgwalters]

For now we'll continue to publish bootupd as a crate,
but I think we should eventually stop doing this.

Closes: #964

[HuijingHei]

Thank you @cgwalters for the workaround, not sure if my understanding is correct, in this case, the dependencies bootc-blockdev and bootc-utils do not have a specified version here, so the publish will fail.

$ git clone https://github.com/cgwalters/bootupd.git -b sync-bootc-code
$ cargo publish --dry-run
    Updating crates.io index
error: all dependencies must have a version specified when publishing.
dependency `bootc-blockdev` does not specify a version
Note: The published dependency will use the version from crates.io,
the `path` specification will be removed from the dependency declaration.

[cgwalters]

Ah right, thanks for testing this out. Yeah I think we're hitting a really longstanding Rust toolchain limitation that requires publishing these sub-crates when what we really want is for them to just be automatically vendored.

I think this PR would need to be reworked to instead rework the sub-crates as modules (very unfortunate ergonomic hit).

xref e.g. https://www.reddit.com/r/rust/comments/10k4q0c/rust_2030_christmas_list_subcrate_dependencies/

[cgwalters]

OK I hacked this up to use modules instead (it's ugly) and it at least compiles locally, but for some reason cargo publish --dry-run seems to fail with

error: couldn't read `src/bootc/blockdev/src/blockdev.rs`: No such file or directory (os error 2)
  --> src/main.rs:53:1
   |
53 | mod bootc_blockdev;
   | ^^^^^^^^^^^^^^^^^^^

error: could not compile `bootupd` (bin "bootupd") due to 1 previous error
error: failed to verify package tarball

No idea about that right now

[cgwalters]

Man it's just so unreasonably difficult to share these little bits of code between two projects without going all the way to publishing as a stable crate, which has a pretty high overhead for what it would give us (especially in making a separate RPM package for it!).

Anyways, I now did bootc-dev/bootc#1394

What I always find really ironic about this from the distro side is that there are no alarms about duplicate code that no one is actively trying to keep in sync.

[HuijingHei]

Man it's just so unreasonably difficult to share these little bits of code between two projects without going all the way to publishing as a stable crate, which has a pretty high overhead for what it would give us (especially in making a separate RPM package for it!).

Anyways, I now did bootc-dev/bootc#1394

This remains the best available solution.

[HuijingHei]

Thank you @cgwalters for fixing the issue.

[HuijingHei]

LGTM