Add ruff rule PERF for performance

[cclauss]

% ruff check --extend-select=C4,C90,PERF,RET,SIM,W

% ruff rule PERF401

manual-list-comprehension (PERF401)

Derived from the Perflint linter.

Fix is sometimes available.

What it does

Checks for for loops that can be replaced by a list comprehension.

Why is this bad?

When creating a transformed list from an existing list using a for-loop,
prefer a list comprehension. List comprehensions are more readable and
more performant.

Using the below as an example, the list comprehension is ~10% faster on
Python 3.11, and ~25% faster on Python 3.10.

Note that, as with all perflint rules, this is only intended as a
micro-optimization, and will have a negligible impact on performance in
most cases.

Example

original = list(range(10000))
filtered = []
for i in original:
    if i % 2:
        filtered.append(i)

Use instead:

original = list(range(10000))
filtered = [x for x in original if x % 2]

If you're appending to an existing list, use the extend method instead:

original = list(range(10000))
filtered.extend(x for x in original if x % 2)

[eustas]

Cool. Thanks.

[cclauss]

Thanks for the review. Three required GitHub Actions workflows need maintainer approval below to run.

[eustas]

No worries about workflows - landing of PR in google/brotli is a bit more complicated than just almost everywhere in GH. You might have noticed that it is "copybara-service" pushes commits...