Bump anstream from 0.6.4 to 0.6.18 in /tools/aigcexmin

Bumps [anstream](https://github.com/rust-cli/anstyle) from 0.6.4 to 0.6.18.
- [Commits](rust-cli/anstyle@anstream-v0.6.4...anstream-v0.6.18)

---
updated-dependencies:
- dependency-name: anstream
  dependency-type: indirect
...

Signed-off-by: dependabot[bot] <[email protected]>