Bump rubocop from 1.35.1 to 1.56.2

Among many things, this version includes updates in the
`Layout/ExtraSpacing`, `Layout/SpaceAroundOperators` and
`Style/RedundantReturn` rules, which means we need to update the code in
some places in order to follow these rules.

Bumps [rubocop](https://github.com/rubocop/rubocop) from 1.35.1 to 1.56.2.
- [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/v1.35.1...v1.56.2)

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

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

Gemfile

@@ -106,7 +106,7 @@ group :development do
   gem "pronto-eslint", "~> 0.11.1", require: false
   gem "pronto-rubocop", "~> 0.11.5", require: false
   gem "pronto-scss", "~> 0.11.0", require: false
-  gem "rubocop", "~> 1.35.1", require: false
+  gem "rubocop", "~> 1.56.2", require: false
   gem "rubocop-performance", "~> 1.19.0", require: false
   gem "rubocop-rails", "~> 2.20.2", require: false
   gem "rubocop-rspec", "~> 2.17.1", require: false

Gemfile.lock

@@ -91,6 +91,7 @@ GEM
     babel-transpiler (0.7.0)
       babel-source (>= 4.0, < 6)
       execjs (~> 2.0)
+    base64 (0.1.1)
     bcrypt (3.1.19)
     better_html (2.0.2)
       actionview (>= 6.0)
@@ -306,6 +307,7 @@ GEM
       rexml
     kramdown-parser-gfm (1.1.0)
       kramdown (~> 2.0)
+    language_server-protocol (3.17.0.3)
     launchy (2.5.2)
       addressable (~> 2.8)
     leaflet-rails (1.9.3)
@@ -513,16 +515,18 @@ GEM
       rspec-mocks (~> 3.10)
       rspec-support (~> 3.10)
     rspec-support (3.11.0)
-    rubocop (1.35.1)
+    rubocop (1.56.2)
+      base64 (~> 0.1.1)
       json (~> 2.3)
+      language_server-protocol (>= 3.17.0)
       parallel (~> 1.10)
-      parser (>= 3.1.2.1)
+      parser (>= 3.2.2.3)
       rainbow (>= 2.2.2, < 4.0)
       regexp_parser (>= 1.8, < 3.0)
       rexml (>= 3.2.5, < 4.0)
-      rubocop-ast (>= 1.20.1, < 2.0)
+      rubocop-ast (>= 1.28.1, < 2.0)
       ruby-progressbar (~> 1.7)
-      unicode-display_width (>= 1.4.0, < 3.0)
+      unicode-display_width (>= 2.4.0, < 3.0)
     rubocop-ast (1.29.0)
       parser (>= 3.2.1.0)
     rubocop-performance (1.19.0)
@@ -742,7 +746,7 @@ DEPENDENCIES
   rinku (~> 2.0.6)
   ros-apartment (~> 2.11.0)
   rspec-rails (~> 5.1.2)
-  rubocop (~> 1.35.1)
+  rubocop (~> 1.56.2)
   rubocop-performance (~> 1.19.0)
   rubocop-rails (~> 2.20.2)
   rubocop-rspec (~> 2.17.1)

app/models/budget/investment.rb

@@ -270,7 +270,7 @@ class Budget
       return permission_problem(user) if permission_problem?(user)
       return :different_heading_assigned unless valid_heading?(user)
 
-      return :no_selecting_allowed unless budget.selecting?
+      :no_selecting_allowed unless budget.selecting?
     end
 
     def reason_for_not_being_ballotable_by(user, ballot)

app/models/legislation/proposal.rb

@@ -73,7 +73,7 @@ class Legislation::Proposal < ApplicationRecord
   def self.search_by_code(terms)
     matched_code = match_code(terms)
     results = where(id: matched_code[1]) if matched_code
-    return results if results.present? && results.first.code == terms
+    results if results.present? && results.first.code == terms
   end
 
   def self.match_code(terms)

app/models/proposal.rb

@@ -145,7 +145,7 @@ class Proposal < ApplicationRecord
   def self.search_by_code(terms)
     matched_code = match_code(terms)
     results = where(id: matched_code[1]) if matched_code
-    return results if results.present? && results.first.code == terms
+    results if results.present? && results.first.code == terms
   end
 
   def self.match_code(terms)