Update cachix/install-nix-action action to v29

[renovate]

This PR contains the following updates:

Package	Type	Update	Change
cachix/install-nix-action	action	major	v27 -> v29

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Release Notes

cachix/install-nix-action (cachix/install-nix-action)

v29

Compare Source

Bumps Nix to 2.24.8 to fix CVE-2024-47174

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Configuration

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[renovate]

Branch automerge failure

This PR was configured for branch automerge. However, this is not possible, so it has been raised as a PR instead.

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• Branch has one or more failed status checks