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

---

Release Notes

actions/checkout (actions/checkout)

v6

Compare Source

---

Configuration

📅 Schedule: Branch creation - At any time (no schedule defined), Automerge - At any time (no schedule defined).

🚦 Automerge: Disabled by config. Please merge this manually once you are satisfied.

♻ Rebasing: Whenever PR becomes conflicted, or you tick the rebase/retry checkbox.

🔕 Ignore: Close this PR and you won't be reminded about this update again.

---

• If you want to rebase/retry this PR, check this box

---

This PR was generated by Mend Renovate. View the repository job log.

[github-actions]

Slowest examples

Top 10 slowest examples (1.22 seconds, 54.51% of total time)

Example	Description	Time in seconds
spec/unit/recipes/host_spec.rb:16	dhcp_host create a dhcpd host and verify config is created properly Creates the class configuration file correctly	0.24943
spec/unit/recipes/class_spec.rb:14	dhcp_class create a dhcpd class with no subclass and verify config is created properly Creates the class configuration file correctly	0.12926
spec/unit/recipes/config_spec.rb:38	dhcp_config create a dhcpd config and verify config is created properly Creates the main configuration file	0.11939
spec/unit/recipes/group_spec.rb:21	dhcp_group create a dhcpd group and verify config is created properly Creates the group configuration file correctly	0.11196
spec/unit/recipes/shared_network_spec.rb:71	dhcp_shared_network create a dhcpd multiple shared network and verify config is created properly Creates the shared network configuration file correctly	0.10804
spec/unit/recipes/class_spec.rb:32	dhcp_class create a dhcpd class with subclass and verify config is created properly Creates the class configuration file correctly	0.10763
spec/unit/recipes/subnet_spec.rb:16	dhcp_subnet create a dhcpd subnet for listening only and verify config is created properly Creates the subnet configuration file correctly	0.10262
spec/unit/recipes/group_spec.rb:27	dhcp_group create a dhcpd group and verify config is created properly Creates the nested host configuration file correctly	0.10251
spec/unit/recipes/config_spec.rb:69	dhcp_config create a dhcpd6 config and verify config is created properly Creates the main configuration file	0.09968
spec/unit/recipes/subnet_spec.rb:98	dhcp_subnet create a dhcpd subnet with parameters as array and verify config is created properly Creates the subnet configuration file correctly	0.0979