* test_foreach: assert on arg _var_type
* [REF-2682] Foreach over dict uses Tuple arg value
When iterating over a Var with _var_type dict, the resulting arg value
_var_type should be Tuple[key, value] so it can be correctly used with other
var operations.
Fix#3157
* Correct _var_type for iteration over Tuple of multiple types
The arg value when iterating over a tuple could be any of the possible values
mentioned in the annotation.
When only one type is used, the Union collapses to the base type, at least in py3.11
* Add comments
* build pyi files when building/publishing 3rd party
* fix typo in workflow
* add future annotation
* add tests to pass coverage check
* add more unit tests
* omit pyi_generator from test coverage
* change black from dev deps to direct deps
* remake all pyi
* format pyi if black is present, return as if otherwise
* fix requested changes
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Co-authored-by: Masen Furer <m_github@0x26.net>
