rust: Filter vendor tarball by default

[travier]

We generally want to filter out non-Linux support from our vendor tarballs.

[travier]

As Benjamin mentioned in #40 (comment), this needs changes in the following repos:

• afterburn - cargo: add configuration for cargo-vendor-filterer afterburn#866
• bootupd
• ignition-config-rs
• openssh-keys
• ssh-key-dir - cargo: add configuration for cargo-vendor-filterer ssh-key-dir#140
• zincati - cargo: add configuration for cargo-vendor-filterer zincati#942

CC @lucab

[travier]

And bootupd (added in #40).
CC @cgwalters

[bgilbert]

ignition-config-rs and openssh-keys aren't affected because they're libraries and don't ship a vendor tarball.

[bgilbert]

I've opened PRs for the remaining projects. In principle we could get this in and let the individual projects merge the checklist updates when they're ready.

[bgilbert]

It turns out that find target/vendor -name '*.a' -delete isn't safe in general, since the rustix crate ships Linux-specific static archives. So I'd favor deleting the non-vendor-filterer case altogether.

[bgilbert]

I've done that in #84. Closing this PR in favor of that one.