Preview rule stabilizations for v0.2.0

[zanieb]

New rules are now added in preview. This issue serves as a central discussion for rules that should be promoted from preview to stable in the next breaking version of Ruff.

[NeilGirdhar]

I tried out the previewed rules, and I got useful hits from:

• E114 Indentation is not a multiple of 4 (comment)
• E116 Unexpected indentation (comment)
• E203 [*] Whitespace before ','
• E241 Multiple spaces after comma
• E271 Multiple spaces after keyword
• FURB113 [*] Use args.extend(...) instead of repeatedly calling args.append()

Also, see this comment on PLR6301

[dhruvmanila]

Do we want to add all the existing rules in preview here as a checklist?

[charliermarsh]

I'd love to drop some duplicate rules in the next minor, e.g., #8830.

[charliermarsh]

I think we should elevate the C rule fixes to "safe". I believe they're unsafe right now because we risk dropping comments, but that's not really the intent of fix safety.

[charliermarsh]

We should also elevate UP006 and UP007 to safe in some cases.

[zanieb]

I'd love to drop some duplicate rules in the next minor, e.g., #8830.

Can we remove rules in preview? If not, maybe we should add a "Deprecated" rule group that acts as removed when preview mode is enabled.

[charliermarsh]

I think we should also deprecate PLR1706 (#9007).