Bump rubocop from 1.71.2 to 1.75.8

Bumps [rubocop](https://github.com/rubocop/rubocop) from 1.71.2 to 1.75.8.
- [Release notes](https://github.com/rubocop/rubocop/releases)
- [Changelog](https://github.com/rubocop/rubocop/blob/master/CHANGELOG.md)
- [Commits](https://github.com/rubocop/rubocop/compare/v1.71.2...v1.75.8)

---
updated-dependencies:
- dependency-name: rubocop
  dependency-version: 1.75.8
  dependency-type: direct:development
  update-type: version-update:semver-minor
...

Notes:

This commit also includes several style and lint fixes required after
updating RuboCop:

- Removed redundant parentheses now detected by improved
  'Style/RedundantParentheses' (1.72 and 1.75.3).
- Replaced ternary expressions with logical OR when the ternary was
  returning 'true', as flagged by 'Style/RedundantCondition' (1.73).
- Adjusted block variables to resolve new 'Lint/ShadowingOuterLocalVariable'
  offenses (1.75), helping avoid future conflicts during upgrades with
  'rails app:updates'

Signed-off-by: dependabot[bot] <support@github.com>

app/components/budgets/groups_and_headings_component.html.erb

@@ -5,7 +5,7 @@
       <% group.headings.sort_by_name.each do |heading| %>
         <li class="heading">
           <%= link_to_unless(
-            (budget.informing? || budget.finished?),
+            budget.informing? || budget.finished?,
             heading.name,
             budget_investments_path(budget.id, heading_id: heading.id)
           ) %>