Update Nix version requirement from 2.13 to 2.18 and switch to nixbuild/nix-quick-install-action@v32

[Copilot]

This PR updates the minimum Nix version requirement from 2.13 to 2.18 to address CI failures caused by nixpkgs requiring a newer Nix version, and switches all GitHub Actions workflows to use nixbuild/nix-quick-install-action@v32 for better performance.

Changes Made

Core Version Update:

• Updated the version assertion in flake.nix from 2.13 to 2.18
• Updated the corresponding error message to reflect the new minimum version requirement

CI Workflow Updates:

• Replaced DeterminateSystems/nix-installer-action@main with nixbuild/nix-quick-install-action@v32 in all workflows
• Updated .github/workflows/std.yml (4 instances across discover, cli, shells, and tests jobs)
• Updated .github/workflows/gh-pages.yaml
• Updated .github/workflows/flakehub-publish-tagged.yml

Context

The CI was failing because the current nixpkgs version requires Nix 2.18 or higher, but the Standard framework was still enforcing a minimum requirement of 2.13. This mismatch caused build failures in the GitHub Actions workflows.

The workflow updates use nixbuild/nix-quick-install-action@v32 which installs Nix 2.18+ that meets the new requirement while providing faster installation times and maintaining cross-platform compatibility for both Linux and macOS runners.

Fixes #411.

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[blaggacao]

@copilot please also update the GH Action workflow files to use the appropriate nix version

[Copilot]

@copilot please also update the GH Action workflow files to use the appropriate nix version

Updated all GitHub Actions workflow files to use DeterminateSystems/nix-installer-action@main instead of nixbuild/nix-quick-install-action@v25. This ensures the workflows use Nix 2.18+ which aligns with the updated requirement in flake.nix.

Changes made in commit 52cf141:

• Updated .github/workflows/std.yml (4 instances across discover, cli, shells, and tests jobs)
• Updated .github/workflows/gh-pages.yaml
• .github/workflows/flakehub-publish-tagged.yml already used the correct action

The DeterminateSystems installer provides recent Nix versions and maintains cross-platform compatibility for both Linux and macOS runners.

[blaggacao]

@copilot I still prefer https://github.com/nixbuild/nix-quick-install-action/releases/tag/v32 - since as I have lernt it was faster at the time. Please refactor to use this action, which includes an appropriate nix version

[Copilot]

@copilot I still prefer https://github.com/nixbuild/nix-quick-install-action/releases/tag/v32 - since as I have lernt it was faster at the time. Please refactor to use this action, which includes an a...

Updated all GitHub Actions workflows to use nixbuild/nix-quick-install-action@v32 for better performance. This version includes Nix 2.18+ which meets the updated requirement while providing faster installation times.

Changes made in commit 3fc7f82:

• Updated .github/workflows/std.yml (4 instances)
• Updated .github/workflows/gh-pages.yaml
• Updated .github/workflows/flakehub-publish-tagged.yml

[blaggacao]

LGTM

[blaggacao]

FYI, #416 in my analysis blocks CI, thus update in this PR. Unfortunately, this is a non-trivial refactor. Let's see how far copilot manages... On the flipside, getting freed from this legacy implementation, removes a major errand of this framework.