chore(deps): update actions/checkout action to v6

[renovate]

This PR contains the following updates:

Package	Type	Update	Change
actions/checkout	action	major	v5 → v6

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Release Notes

actions/checkout (actions/checkout)

v6

Compare Source

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Configuration

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Slowest examples

Top 10 slowest examples (0.01 seconds, 74.4% of total time)

Example	Description	Time in seconds
spec/libraries/chef_graphite_python_spec.rb:10	ChefGraphite::PythonWriter#to_s takes a nil config has and returns an empty string	0.01076
spec/libraries/mixins_spec.rb:25	ChefGraphite::Mixins.resources_to_hashes returns an array of hashes with types set given a whitelist	0.00037
spec/libraries/mixins_spec.rb:32	ChefGraphite::Mixins.resources_to_hashes returns an array of hashes with nil types when no whitelist is given	0.00026
spec/libraries/chef_graphite_python_spec.rb:29	ChefGraphite::PythonWriter#to_s takes a hash and writes the python config	0.00023
spec/libraries/chef_graphite_python_spec.rb:54	ChefGraphite::PythonWriter#to_s takes a hash and writes the python config with uppercase root keys	0.00022
spec/libraries/chef_graphite_python_spec.rb:14	ChefGraphite::PythonWriter#to_s takes an empty config hash and returns an empty string	0.00021
spec/libraries/chef_graphite_python_spec.rb:121	ChefGraphite::PythonWriter#pythonize renders a hash with false values as a python dictionary	0.00021
spec/libraries/chef_graphite_python_spec.rb:89	ChefGraphite::PythonWriter#pythonize renders a string value as a quoted string	0.00021
spec/libraries/chef_graphite_python_spec.rb:18	ChefGraphite::PythonWriter#to_s takes a ruby hash and returns a string joined with new lines	0.0002
spec/libraries/chef_graphite_spec.rb:36	ChefGraphite.generate_conf_data for config normalizes string key names to uppercase	0.0002