Add support for archive log type "6"

[GeoTime61]

Most caches use an archive log type of "5", but some caches use an archive type of "6". Retain support for type "5" and add support for type "6".

[GeoTime61]

I don't know anything about GitHub, but I did my best to create a pull request with the change and a simple test.

Following the steps in CONTRIBUTING:
"isort ." worked.
"black ." worked.
"flake8" failed - AttributeError: 'EntryPoints' object has no attribute 'get'
"pytest test" (had to add " test") failed - FAIL Required test coverage of 90% not reached. Total coverage: 89.90%

Maybe you can tell me what I did wrong or help me fix the errors.

[FriedrichFroebel]

Thanks for the PR.

Running python -m pip install .[dev] before running flake8 or pytest should in theory not yield any issues and work out of the box - different versions might yield different results. The GitHub Actions CI is using the same commands without any real issues.

[FriedrichFroebel]

LGTM.