build(deps): bump cachix/install-nix-action from v12 to v13

Bumps cachix/install-nix-action from v12 to v13.

Signed-off-by: dependabot[bot] <support@github.com>

Created by  dependabot[bot]  on April 5, 2021
IEL43MSUZFNRZUZKXNU4PCOYMA65TSTQL5LKSZETILBB7HHJZADAC
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