Adding a license file during clarification doesn't work for nested files

[Will-Low]

Describe the bug
When I try to add multiple license files to the license-files field, and the path of one of those license files is nested in a subdirectory, I'm getting a "unable to locate specified license file" message.

To Reproduce
I'm adding a clarification for rustls-webpki. My clarification looks like:

[[licenses.clarify]]
name = "rustls-webpki"
expression = "BSD-3-Clause AND MPL-2.0"
license-files = [
    { path = "LICENSE", hash = 0x001c7e6c },
    { path = "third-party/chromium/LICENSE", hash = 0x001c7e6c },
]

The first license file is the MPL-2.0 and the second is the BSD-3-Clause. The path for the second file exists in the published crate. See https://docs.rs/crate/rustls-webpki/0.100.1/source/third-party/chromium/LICENSE.

Note that the hash for the second file is wrong; I don't know what it is yet to add it.

My output:

error[unlicensed]: rustls-webpki = 0.100.1 is unlicensed
   ┌─ /Users/NAME/repos/REPO/deny.toml:44:14
   │
44 │     { path = "third-party/chromium/LICENSE", hash = 0x001c7e6c },
   │              ------------------------------ unable to locate specified license file
   │
   ┌─ rustls-webpki 0.100.1 (registry+https://github.com/rust-lang/crates.io-index):2:9
   │
 2 │ name = "rustls-webpki"
   │         ^^^^^^^^^^^^^ a valid license expression could not be retrieved for the crate
 3 │ version = "0.100.1"
 4 │ license = ""
   │            - license expression was not specified
 5 │ license-files = [
 6 │     { path = "LICENSE", hash = 0x001c7e6c, score = 0.85, license = "ISC" },
   │                                                    ---- low confidence in the license text
   │
   = rustls-webpki v0.100.1
     └── rustls v0.21.0
         ...

warning[license-exception-not-encountered]: license exception was not encountered
   ┌─ /Users/NAME/repos/REPO/deny.toml:58:8
   │
58 │ name = "rustls-webpki"
   │        ^^^^^^^^^^^^^^^ unmatched license exception

licenses FAILED

Expected behavior
I would expect an error telling me that the crate is unlicensed, giving me the hash of the second license file, which I would then include.

Device:

• OS: macOS 13.4

[Jake-Shadle]

Note that while I am fixing this because it is a bug, the particular error case in the description is unnecessary IMO, the third-party/chromium/LICENSE applies to the test data in that directory which is only used for the internal crate testing, and not part of the actual distributed crate package.

[Jake-Shadle]

Oh and even better, later versions of rustls-webpki also just correctly set the license field so clarifications are not even needed.