chore: update deny.toml (#2888)

## Description

icu switched from some draft unicode licence to unicode-3.0. It's
basically MIT with some seasoning.

## Breaking Changes

<!-- Optional, if there are any breaking changes document them,
including how to migrate older code. -->

## Notes & open questions

<!-- Any notes, remarks or open questions you have to make about the PR.
-->

## Change checklist

- [ ] Self-review.
- [ ] Documentation updates following the [style
guide](https://rust-lang.github.io/rfcs/1574-more-api-documentation-conventions.html#appendix-a-full-conventions-text),
if relevant.
- [ ] Tests if relevant.
- [ ] All breaking changes documented.

Author: Arqu

deny.toml

@@ -21,6 +21,7 @@ allow = [
       "Unicode-DFS-2016",
       "Zlib",
       "MPL-2.0", # https://fossa.com/blog/open-source-software-licenses-101-mozilla-public-license-2-0/
+      "Unicode-3.0",
 ]
 
 [[licenses.clarify]]