✔️ Validator: TITLE

• ✔️ All the requisite validations passed for 'or' option
  Input : refactor: Don't expose Tox_System in the public API
  Settings : {"or":[{"must_include":{"regex":"^(feat|docs|chore|cleanup|fix|refactor|test|style|perf)(\\(\\w+\\))?:\\ .+$","message":"Semantic release conventions must be followed."}},{"must_include":{"regex":"^Bump [^ ]* from [^ ]* to [^ ]*$","message":"Dependabot PRs are exempt from semantic release conventions."}}]}

✔️ Validator: COMMIT

• ✔️ Your commit messages met the specified criteria
  Input : refactor: Don't expose Tox_System in the public API

It makes no sense to include it in the public API as clients can't make
any meaningful use of it via public API, it can only be used if one also
includes other internal/private headers that we don't install.

It's used only in the testing code, which has access to the internal
headers.

Fixes #2739, at least to some degree. I decided against moving things to
a separate tox_testing.h and leaving only things in tox_private.h
that we are fine with clients using, as otherwise tox_lock() /
tox_unlock() would have to be moved out of tox_private.h to
somewhere else, but tox_private.h actually sounds like the right place
for them, naming-wise. So perhaps it's fine if we have things in
tox_private.h that we don't want clients to use.
Settings : {"do":"commit","message":{"regex":"^((feat|docs|chore|cleanup|fix|refactor|test|style|perf)(\\(\\w+\\))?:\\ .+|Bump [^ ]* from [^ ]* to [^ ]*)","message":"Semantic release conventions must be followed."}}

✔️ Validator: DESCRIPTION

• ✔️ description must exclude '\[ \]'
  Input : It makes no sense to include it in the public API as clients can't make any meaningful use of it via public API, it can only be used if one also includes other internal/private headers that we don't install.

It's used only in the testing code, which has access to the internal headers.

Fixes #2739, at least to some degree. I decided against moving things to a separate tox_testing.h and leaving only things in tox_private.h that we are fine with clients using, as otherwise tox_lock() / tox_unlock() would have to be moved out of tox_private.h to somewhere else, but tox_private.h actually sounds like the right place for them, naming-wise. So perhaps it's fine if we have things in tox_private.h that we don't want clients to use.

This change is 

Settings : {"must_exclude":{"regex":"\\\\[ \\\\]","message":"There are incomplete TODO task(s) unchecked."}}