Bump indexmap from 1.3.2 to 1.6.0 (#674)
Bump indexmap from 1.3.2 to 1.6.0 (#674)

Bumps [indexmap](https://github.com/bluss/indexmap) from 1.3.2 to 1.6.0.
- [Release notes](https://github.com/bluss/indexmap/releases)
- [Commits](https://github.com/bluss/indexmap/compare/1.3.2...1.6.0)

Signed-off-by: dependabot[bot] <5bdcd3c0d4d24ae3e71b3b452a024c6324c7e4bb@github.com>

Co-authored-by: dependabot[bot] <1c358da00a777d4e9898c1280ab801e2df165188@users.noreply.github.com>
alex/ct-tools,alex/ct-tools