Update doctr recipe to 1.3.1

[asmeurer]

No description provided.

[conda-forge-linter]

Hi! This is the friendly automated conda-forge-linting service.

I just wanted to let you know that I linted all conda-recipes in your PR (recipe) and found it was in an excellent condition.

[asmeurer]

Seems to be a bug in something. CC @conda-forge/core

Using Anaconda API: https://api.anaconda.org
Traceback (most recent call last):
  File "/feedstock_root/ci_support/upload_or_check_non_existence.py", line 124, in <module>
    main()
  File "/feedstock_root/ci_support/upload_or_check_non_existence.py", line 104, in main
    exists = built_distribution_already_exists(cli, meta, owner)
  File "/feedstock_root/ci_support/upload_or_check_non_existence.py", line 24, in built_distribution_already_exists
    fname = bldpkg_path(meta)
TypeError: bldpkg_path() missing 1 required positional argument: 'config'

./ci_support/run_docker_build.sh returned exit code 1