verifier-cli should not depend on libipcc

[jclulow]

We ship dice-util and verifier-cli to the programming stations in a package. We build the binaries with:

cargo build --release --locked \
    --bin dice-mfg \
    --bin verifier-cli

Unfortunately this now produces a verifier-cli that depends on libipcc.so.1. There is no IPCC interface available on the programming stations, so this ought not to be necessary.

$ elfdump -d target/release/verifier-cli | grep NEED
       [0]  NEEDED            0x14dd71            libipcc.so.1
       [1]  NEEDED            0x14dd8d            libsocket.so.1
       [2]  NEEDED            0x14ddcc            librt.so.1
       [3]  NEEDED            0x14dde0            libpthread.so.1
       [4]  NEEDED            0x14ddf9            libnsl.so.1
       [5]  NEEDED            0x14de15            libumem.so.1
       [6]  NEEDED            0x14de22            libgcc_s.so.1
       [7]  NEEDED            0x14de4a            libc.so.1
      [23]  VERNEED           0x60b6e0
      [24]  VERNEEDNUM        0x8

[flihp]

if the ipcc feature is omitted when the verifier-cli is built the right bits are disabled in the tool (no ipcc interface / backend available when executing it). However, if built on a system w/ libipcc installed the elf data lists libipcc as NEEDED whether or not the feature is enabled. This is not the behavior that we want.

[jclulow]

FWIW, it's not clear that libipcc being installed or not is what actually made the choice here, because the built binary didn't include the directory for it in the RUNPATH so I'm not sure it knew it was there per se.

[flihp]

looks like this was a regression caused by #342: I added a new crate to the workspace that unconditionally depends on libipcc. Turns out that even if you build only the verifier-cli, this new crate causes cargo to pull in the libipcc dependency. This is not the behavior that I expected but I reverted this commit and now elfdump no longer sees libipcc.so.1 as NEEDED by verifier-cli.

[flihp]

I'll get to the bottom of this tomorrow but for the short term I'll revert the commit on main to keep things moving. Will fix this new crate tomorrow.