Fix some typing issues in P2P, expansion toys #1693

Job	Run time
Ruff	4s
Documentation	20s
Conda Pytest Symengine	5s
Conda Examples	16s
Tests for downstream project pytential	13s
basedpyright	3s
Pylint	20s
Typos	3s
Conda Pytest	3s
	1m 27s

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