Simplify using flake8-simplify

[cclauss]

% ruff --select=SIM108,SIM118 --fix .

Found 7 errors (7 fixed, 0 remaining).

% ruff rule SIM108

if-else-block-instead-of-if-exp (SIM108)

Derived from the flake8-simplify linter.

Autofix is sometimes available.

Message formats:

• Use ternary operator {contents} instead of if-else-block

% ruff rule SIM118

in-dict-keys (SIM118)

Derived from the flake8-simplify linter.

Autofix is always available.

Message formats:

• Use {key} in {dict} instead of {key} in {dict}.keys()

[acdha]

I would disable this. It’s harder to read, generates more diff noise if you change either branch, and vertical height isn’t a strictly limited resource.

[cclauss]

Closing in favor of #392