build(deps): bump writeable from 0.6.3 to 0.6.4 (#8670)

Bumps [writeable](https://github.com/unicode-org/icu4x) from 0.6.3 to 0.6.4.
- [Release notes](https://github.com/unicode-org/icu4x/releases)
- [Changelog](https://github.com/unicode-org/icu4x/blob/main/CHANGELOG.md)
- [Commits](https://github.com/unicode-org/icu4x/commits)

---
updated-dependencies:
- dependency-name: writeable
  dependency-version: 0.6.4
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Cargo.lock

@@ -4878,9 +4878,9 @@ checksum = "d1890f4022759daae28ed4fe62859b1236caebfc61ede2f63ed4e695f3f6d936"
 
 [[package]]
 name = "writeable"
-version = "0.6.3"
+version = "0.6.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1ffae5123b2d3fc086436f8834ae3ab053a283cfac8fe0a0b8eaae044768a4c4"
+checksum = "3ad82d2a33cdc9674dc7465672f271e096168fcdbe0f799d9e6db8c5892679dc"
 
 [[package]]
 name = "x509-cert"