feat(linter): add redundancy rules for literal returns and inline variables

- Add `no-redundant-literal-return` rule to detect patterns like `if ($x === null) { return null; } return $x;`
- Add `inline-variable-return` rule to detect patterns like `$x = getValue(); return $x;`

Signed-off-by: azjezz <[email protected]>

Author: azjezz

crates/linter/src/rule/mod.rs

@@ -193,6 +193,7 @@ define_rules! {
     NoRedundantNullsafe(no_redundant_nullsafe @ NoRedundantNullsafeRule),
     NoRedundantMath(no_redundant_math @ NoRedundantMathRule),
     NoRedundantLabel(no_redundant_label @ NoRedundantLabelRule),
+    NoRedundantLiteralReturn(no_redundant_literal_return @ NoRedundantLiteralReturnRule),
     NoRedundantFinal(no_redundant_final @ NoRedundantFinalRule),
     NoRedundantReadonly(no_redundant_readonly @ NoRedundantReadonlyRule),
     NoRedundantFile(no_redundant_file @ NoRedundantFileRule),
@@ -227,6 +228,7 @@ define_rules! {
     LowercaseTypeHint(lowercase_type_hint @ LowercaseTypeHintRule),
     IdentityComparison(identity_comparison @ IdentityComparisonRule),
     IneffectiveFormatIgnoreNext(ineffective_format_ignore_next @ IneffectiveFormatIgnoreNextRule),
+    InlineVariableReturn(inline_variable_return @ InlineVariableReturnRule),
     IneffectiveFormatIgnoreRegion(ineffective_format_ignore_region @ IneffectiveFormatIgnoreRegionRule),
     InstanceofStringable(instanceof_stringable @ InstanceofStringableRule),
     InterfaceName(interface_name @ InterfaceNameRule),