Reduce minimum RuboCop version back to ~> 1.51

Since we're introducing the

    <% if rubocop_version >= "X.YZ"
    Dept/Cop:
      Enabled: true
    <% end %>

approach to configuring RuboCop without requiring a specific version of
the gem (ahead of supporting plugin configs), we should just use that
approach to avoid changing the minimum required version in the next
release.

Gemfile.lock

@@ -2,7 +2,7 @@ PATH
   remote: .
   specs:
     rubocop-shopify (2.14.0)
-      rubocop (~> 1.53)
+      rubocop (~> 1.51)
 
 GEM
   remote: https://rubygems.org/

rubocop-shopify.gemspec

@@ -23,5 +23,5 @@ Gem::Specification.new do |s|
 
   s.required_ruby_version = ">= 2.7.0"
 
-  s.add_dependency("rubocop", "~> 1.53")
+  s.add_dependency("rubocop", "~> 1.51")
 end

rubocop.yml

@@ -202,8 +202,10 @@ Lint/LiteralAssignmentInCondition:
   Enabled: true
 <% end %>
 
+<% if rubocop_version >= "1.53" %>
 Lint/MixedCaseRange:
   Enabled: true
+<% end %>
 
 Lint/MixedRegexpCaptureTypes:
   Enabled: false
@@ -238,8 +240,10 @@ Lint/RaiseException:
 Lint/RedundantDirGlobSort:
   Enabled: false
 
+<% if rubocop_version >= "1.53" %>
 Lint/RedundantRegexpQuantifiers:
   Enabled: true
+<% end %>
 
 Lint/RedundantRequireStatement:
   Enabled: false
@@ -726,8 +730,10 @@ Style/RandomWithOffset:
 Style/RedundantArgument:
   Enabled: false
 
+<% if rubocop_version >= "1.52" %>
 Style/RedundantArrayConstructor:
   Enabled: true
+<% end %>
 
 Style/RedundantAssignment:
   Enabled: false
@@ -741,8 +747,10 @@ Style/RedundantConditional:
 Style/RedundantConstantBase:
   Enabled: true
 
+<% if rubocop_version >= "1.53" %>
 Style/RedundantCurrentDirectoryInPath:
   Enabled: true
+<% end %>
 
 Style/RedundantDoubleSplatHashBraces:
   Enabled: true
@@ -756,8 +764,10 @@ Style/RedundantFetchBlock:
 Style/RedundantFileExtensionInRequire:
   Enabled: false
 
+<% if rubocop_version >= "1.52" %>
 Style/RedundantFilterChain:
   Enabled: true
+<% end %>
 
 Style/RedundantHeredocDelimiterQuotes:
   Enabled: true
@@ -768,14 +778,18 @@ Style/RedundantInitialize:
 Style/RedundantLineContinuation:
   Enabled: true
 
+<% if rubocop_version >= "1.53" %>
 Style/RedundantRegexpArgument:
   Enabled: true
+<% end %>
 
 Style/RedundantRegexpCharacterClass:
   Enabled: false
 
+<% if rubocop_version >= "1.52" %>
 Style/RedundantRegexpConstructor:
   Enabled: true
+<% end %>
 
 Style/RedundantRegexpEscape:
   Enabled: false
@@ -801,8 +815,10 @@ Style/RescueStandardError:
 Style/ReturnNil:
   Enabled: true
 
+<% if rubocop_version >= "1.53" %>
 Style/ReturnNilInPredicateMethodDefinition:
   Enabled: true
+<% end %>
 
 Style/SelectByRegexp:
   Enabled: false
@@ -874,8 +890,10 @@ Style/UnpackFirst:
 Style/WordArray:
   EnforcedStyle: brackets
 
+<% if rubocop_version >= "1.53" %>
 Style/YAMLFileRead:
   Enabled: true
+<% end %>
 
 Style/YodaCondition:
   Enabled: false