Revert "[Ruff 0.6] Stabilise PLR6104 (#12858)"

This reverts commit cea8d57.

crates/ruff_linter/src/codes.rs

@@ -262,7 +262,7 @@ pub fn code_to_rule(linter: Linter, code: &str) -> Option<(RuleGroup, Rule)> {
         (Pylint, "R2004") => (RuleGroup::Stable, rules::pylint::rules::MagicValueComparison),
         (Pylint, "R2044") => (RuleGroup::Stable, rules::pylint::rules::EmptyComment),
         (Pylint, "R5501") => (RuleGroup::Stable, rules::pylint::rules::CollapsibleElseIf),
-        (Pylint, "R6104") => (RuleGroup::Stable, rules::pylint::rules::NonAugmentedAssignment),
+        (Pylint, "R6104") => (RuleGroup::Preview, rules::pylint::rules::NonAugmentedAssignment),
         (Pylint, "R6201") => (RuleGroup::Preview, rules::pylint::rules::LiteralMembership),
         (Pylint, "R6301") => (RuleGroup::Preview, rules::pylint::rules::NoSelfUse),
         (Pylint, "W0108") => (RuleGroup::Preview, rules::pylint::rules::UnnecessaryLambda),

crates/ruff_linter/src/rules/pylint/rules/non_augmented_assignment.rs

@@ -14,12 +14,12 @@ use crate::checkers::ast::Checker;
 /// statements.
 ///
 /// ## Why is this bad?
-/// If the right-hand side of an assignment statement consists of a binary
-/// operation in which one operand is the same as the assignment target,
-/// it can be rewritten as an augmented assignment. For example, `x = x + 1
-/// can be rewritten as `x += 1`.
+/// If an assignment statement consists of a binary operation in which one
+/// operand is the same as the assignment target, it can be rewritten as an
+/// augmented assignment. For example, `x = x + 1` can be rewritten as
+/// `x += 1`.
 ///
-/// When performing such an operation, an augmented assignment is more concise
+/// When performing such an operation, augmented assignments are more concise
 /// and idiomatic.
 ///
 /// ## Known problems
@@ -31,7 +31,7 @@ use crate::checkers::ast::Checker;
 /// For example, `x = "prefix-" + x` is not equivalent to `x += "prefix-"`,
 /// while `x = 1 + x` is equivalent to `x += 1`.
 ///
-/// If the type of the left-hand side cannot be trivially inferred, the rule
+/// If the type of the left-hand side cannot be inferred trivially, the rule
 /// will ignore the assignment.
 ///
 /// ## Example