update zip to 4.2.0

[sunshowers]

The zip crate's versions 2.6.0 and 2.6.1 were yanked from crates.io: zip-rs/zip2#337

This is currently causing rust-analyzer to barf on Omicron while trying to
fetch cargo metadata:

% RUSTC_BOOTSTRAP=1 /opt/rustup/toolchains/1.87.0-x86_64-unknown-linux-gnu/bin/cargo metadata --format-version 1 --manifest-path /home/rain/dev/oxide/omicron/Cargo.toml --filter-platform x86_64-unknown-linux-gnu --lockfile-path /home/rain/dev/oxide/omicron/target/rust-analyzer/metadata/workspace/Cargo.lock -Zunstable-options
    Updating git repository `https://github.com/oxidecomputer/pq-sys`
    Updating crates.io index
    Updating git repository `https://github.com/oxidecomputer/lldp`
    Updating git repository `https://github.com/oxidecomputer/maghemite`
    Updating git repository `https://github.com/oxidecomputer/serde_human_bytes`
    Updating git repository `https://github.com/oxidecomputer/slog-error-chain`
    Updating git repository `https://github.com/oxidecomputer/tufaceous`
    Updating git repository `https://github.com/oxidecomputer/propolis`
    Updating git repository `https://github.com/oxidecomputer/crucible`
    Updating git repository `https://github.com/oxidecomputer/opte`
    Updating git repository `https://github.com/oxidecomputer/falcon`
    Updating git repository `https://github.com/oxidecomputer/clickward`
    Updating git repository `https://github.com/oxidecomputer/openapi-lint`
    Updating git repository `https://github.com/oxidecomputer/management-gateway-service`
    Updating git repository `https://github.com/oxidecomputer/ipcc-rs`
    Updating git repository `https://github.com/oxidecomputer/dendrite`
    Updating git repository `https://github.com/oxidecomputer/transceiver-control`
    Updating git repository `https://github.com/oxidecomputer/hubtools.git`
    Updating git repository `https://github.com/oxidecomputer/sprockets.git`
    Updating git repository `https://github.com/oxidecomputer/tofino`
    Updating git repository `https://github.com/oxidecomputer/illumos-devinfo`
    Updating git repository `https://github.com/oxidecomputer/libefi-illumos`
    Updating git repository `https://github.com/oxidecomputer/libnvme`
    Updating git repository `https://github.com/bluecatengineering/dhcproto.git`
    Updating git repository `https://github.com/oxidecomputer/ispf`
    Updating git repository `https://github.com/oxidecomputer/netadm-sys`
    Updating git repository `https://github.com/oxidecomputer/propolis`
    Updating git repository `https://github.com/oxidecomputer/transceiver-control`
    Updating git repository `https://github.com/oxidecomputer/tlvc.git`
    Updating git repository `https://github.com/oxidecomputer/lpc55_support`
    Updating git repository `https://github.com/oxidecomputer/tlvc`
    Updating git repository `https://github.com/oxidecomputer/dice-util`
error: failed to select a version for the requirement `zip = "^2.6.0"`
  version 2.6.0 is yanked
  version 2.6.1 is yanked
location searched: crates.io index
required by package `tufaceous-lib v0.1.0 (https://github.com/oxidecomputer/tufaceous?branch=main#04681f26)`
    ... which satisfies git dependency `tufaceous-lib` of package `omicron-nexus v0.1.0 (/home/rain/dev/oxide/omicron/nexus)`
    ... which satisfies path dependency `omicron-nexus` of package `omicron-omdb v0.1.0 (/home/rain/dev/oxide/omicron/dev-tools/omdb)`