Add support for workspace dependencies

[regexident]

Given a workspace Cargo.toml file looking like this:

[workspace]
members = [
    "lilliput-core",
    "lilliput-float",
    "lilliput-serde",
]

# ...

[workspace.dependencies]
criterion = { version = "0.6", features = ["html_reports"] }
proptest = { version = "1.9.0" }
proptest-derive = { version = "0.7.0" }
rand = "0.9.0"
rand_xorshift = "0.4.0"
serde = { version = "1.0.197", default-features = false }
test-log = { version = "0.2.17", features = ["trace"] }
thiserror = "2.0.12"
tracing = { version = "0.1.41" }

Running the following command:

cargo outdated -R --workspace

Produces the following output with cargo-outdated@0.17.0:

lilliput-core
================
Name         Project  Compat  Latest   Kind    Platform
----         -------  ------  ------   ----    --------
ordermap     0.5.7    ---     1.1.0    Normal  ---
serde_bytes  0.11.17  ---     0.11.19  Normal  ---

lilliput-serde
================
Name         Project  Compat  Latest   Kind         Platform
----         -------  ------  ------   ----         --------
indexmap     2.9.0    ---     2.13.0   Normal       ---
insta        1.46.2   ---     1.46.3   Development  ---
serde_bytes  0.11.17  ---     0.11.19  Development  ---

And the following output with this PR:

Workspace
================
Name             Project  Compat  Latest  Kind         Platform
----             -------  ------  ------  ----         --------
criterion        0.6.0    ---     0.8.2   Development  ---
proptest         1.9.0    ---     1.10.0  Development  ---
proptest         1.9.0    ---     1.10.0  Normal       ---
proptest-derive  0.7.0    ---     0.8.0   Development  ---
proptest-derive  0.7.0    ---     0.8.0   Normal       ---
rand             0.9.0    ---     0.10.0  Development  ---
rand_xorshift    0.4.0    ---     0.5.0   Development  ---
test-log         0.2.17   ---     0.2.19  Development  ---
thiserror        2.0.12   ---     2.0.18  Normal       ---
tracing          0.1.41   ---     0.1.44  Normal       ---

lilliput-core
================
Name         Project  Compat  Latest   Kind    Platform
----         -------  ------  ------   ----    --------
ordermap     0.5.7    ---     1.1.0    Normal  ---
serde_bytes  0.11.17  ---     0.11.19  Normal  ---

lilliput-serde
================
Name         Project  Compat  Latest   Kind         Platform
----         -------  ------  ------   ----         --------
indexmap     2.9.0    ---     2.13.0   Normal       ---
insta        1.46.2   ---     1.46.3   Development  ---
serde_bytes  0.11.17  ---     0.11.19  Development  ---

Fixes #360