Specify `Any` for `PyGraph` and `PyDiGraph` type annotations for pyright compatibility

[IvanIsCoding]

Closes #1242

This is a pretty annoying PR but it avoids pyright from infering the types as Unknown. Although we will only keep mypy in the CI, pyright is the base for pylance which ships with VSCode. And we got VSCode issues in the past (#832), so I think it's worth supporting.

[coveralls]

Pull Request Test Coverage Report for Build 10675939721

Details

• 0 of 0 changed or added relevant lines in 0 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage remained the same at 95.817%

---

Totals
Change from base Build 10672676557:	0.0%
Covered Lines:	18051
Relevant Lines:	18839

---

💛 - Coveralls