chore: daily flake.lock update (#5297)

Automated changes by the [update-flake-lock](https://github.com/DeterminateSystems/update-flake-lock) GitHub Action.
as defined in [.github/workflows/update-flake-lock.yml](https://github.com/dfinity/motoko/blob/master/.github/workflows/update-flake-lock.yml)
and run in: https://github.com/dfinity/motoko/actions/runs/15961056658/attempts/1:

```
Flake lock file updates:

• Updated input 'nix-update-flake':
    'github:Mic92/nix-update/f612fb07436603c68f7d90659d4d6ef82b03a5e6?narHash=sha256-xm2zXjvsQxtr3ipRmXDfetd65VMorICq7F9mtiOaVFw%3D' (2025-06-26)
  → 'github:Mic92/nix-update/0e366c09ae7769a4e334e7fb98acdfcd78dc1f66?narHash=sha256-4O4jfNCbPl6Nb6qxrWAzBFN/2I0mDDfGuuIuv2wyn58%3D' (2025-06-30)
```

Author: pr-automation-bot-public[bot]