maintain RubuCop new rules

[Olle Jonsson]

Basic Info

• Faraday Version: latest code
• Ruby Version: n/a

Issue description

RuboCop adds a bunch of new rules.

Gemspec/RequireMFA: # new in 1.23
  Enabled: true
Layout/LineContinuationLeadingSpace: # new in 1.31
  Enabled: true
Layout/LineContinuationSpacing: # new in 1.31
  Enabled: true
Lint/AmbiguousOperatorPrecedence: # new in 1.21
  Enabled: true
Lint/ConstantOverwrittenInRescue: # new in 1.31
  Enabled: true
Lint/IncompatibleIoSelectWithFiberScheduler: # new in 1.21
  Enabled: true
Lint/NonAtomicFileOperation: # new in 1.31
  Enabled: true
Lint/RefinementImportMethods: # new in 1.27
  Enabled: true
Lint/RequireRangeParentheses: # new in 1.32
  Enabled: true
Lint/RequireRelativeSelfPath: # new in 1.22
  Enabled: true
Lint/UselessRuby2Keywords: # new in 1.23
  Enabled: true
Naming/BlockForwarding: # new in 1.24
  Enabled: true
Security/CompoundHash: # new in 1.28
  Enabled: true
Security/IoMethods: # new in 1.22
  Enabled: true
Style/EmptyHeredoc: # new in 1.32
  Enabled: true
Style/EnvHome: # new in 1.29
  Enabled: true
Style/FetchEnvVar: # new in 1.28
  Enabled: true
Style/FileRead: # new in 1.24
  Enabled: true
Style/FileWrite: # new in 1.24
  Enabled: true
Style/MapCompactWithConditionalBlock: # new in 1.30
  Enabled: true
Style/MapToHash: # new in 1.24
  Enabled: true
Style/NestedFileDirname: # new in 1.26
  Enabled: true
Style/NumberedParameters: # new in 1.22
  Enabled: true
Style/NumberedParametersLimit: # new in 1.22
  Enabled: true
Style/ObjectThen: # new in 1.28
  Enabled: true
Style/OpenStructUse: # new in 1.23
  Enabled: true
Style/RedundantInitialize: # new in 1.27
  Enabled: true
Style/SelectByRegexp: # new in 1.22
  Enabled: true
Performance/ConcurrentMonotonicTime: # new in 1.12
  Enabled: true
Performance/MapCompact: # new in 1.11
  Enabled: true
Performance/StringIdentifierArgument: # new in 1.13
  Enabled: true