home-environment: change runCommand to runCommandLocal

[irisjae]

Change runCommand to runCommandLocal so that config changes can build offline without unnecessarily consulting substituters.

A fresh home-manager-generation runCommand derivation is created for each config change, but it should really be runCommandLocal, as it is exceedingly improbable that my config will be cached. Furthermore, this causes NixOS rebuilds to fail offline even if only text config changes are applied, as runCommand causes home-manager to ask Nix to always try consulting substituters and fail if it is unreachable.

A number of other runCommands are also in this module; can someone review if they should also be changed to runCommandLocal?

Description

Checklist

• Change is backwards compatible.

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