cargo: bump mailparse from 0.13.7 to 0.13.8

Bumps [mailparse](https://github.com/staktrace/mailparse) from 0.13.7 to 0.13.8.
- [Release notes](https://github.com/staktrace/mailparse/releases)
- [Commits](https://github.com/staktrace/mailparse/compare/v0.13.7...v0.13.8)

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

Signed-off-by: dependabot[bot] <support@github.com>

Cargo.lock

@@ -2185,12 +2185,12 @@ dependencies = [
 
 [[package]]
 name = "mailparse"
-version = "0.13.7"
+version = "0.13.8"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d70ae0840b192a2f7d1dc46e75f38720a7e3c52dfdc968ba3202fa270668dc67"
+checksum = "8cae768a50835557749599277fc59f7c728118724eb34185e8feb633ef266a32"
 dependencies = [
- "base64 0.13.0",
  "charset",
+ "data-encoding",
  "quoted_printable",
 ]