Release v3.8.1 (#1608)

* Prepare release v3.8.1

* Update test fixtures with the new nix-installer version

* flake.lock: Update

Flake lock file updates:

• Updated input 'determinate':
    'https://api.flakehub.com/f/pinned/DeterminateSystems/determinate/3.8.0/0197f566-d0fc-79a1-9816-7064a5f6d367/source.tar.gz?narHash=sha256-b2ot8YUldB6pEYu5LCTz1eWOiRvZm9A33T20E/359fM%3D' (2025-07-10)
  → 'https://api.flakehub.com/f/pinned/DeterminateSystems/determinate/3.8.1/0197fbf9-0c79-758d-ba83-0b49bf1b63ec/source.tar.gz?narHash=sha256-/qH6AhaKS5hnA7jnZI5HAi8j50yDvBv1ouFXVrRmxIg%3D' (2025-07-12)
• Updated input 'determinate/determinate-nixd-aarch64-darwin':
    'https://install.determinate.systems/determinate-nixd/tag/v3.8.0/macOS?narHash=sha256-/D0JRGZLKXFGN/v1m93ngSy0HJwXlJ6LatVzSGieZr8%3D'
  → 'https://install.determinate.systems/determinate-nixd/tag/v3.8.1/macOS?narHash=sha256-6EHH1qxKU%2BSNIrakf7LELeZZEq/e1OvgE%2BY00F62Q7o%3D'
• Updated input 'determinate/determinate-nixd-aarch64-linux':
    'https://install.determinate.systems/determinate-nixd/tag/v3.8.0/aarch64-linux?narHash=sha256-0OnIHMVLlg4KrFjeZ%2BavljXqAMCi5nlAl%2BU6rFFTJ8Y%3D'
  → 'https://install.determinate.systems/determinate-nixd/tag/v3.8.1/aarch64-linux?narHash=sha256-p5wVPWmp2q%2BsXMzBTFwGzbYB/b2/nqEgQKmJGciNZr4%3D'
• Updated input 'determinate/determinate-nixd-x86_64-linux':
    'https://install.determinate.systems/determinate-nixd/tag/v3.8.0/x86_64-linux?narHash=sha256-2P2B9%2BOl0VmDzjJRnrwH5w63vK78HXsaeNGSYMv3GhM%3D'
  → 'https://install.determinate.systems/determinate-nixd/tag/v3.8.1/x86_64-linux?narHash=sha256-rWY/fbvT7QmmSybgGvVgU6fuLwGOLhG7Uo4qlUGrGLU%3D'
• Updated input 'nix':
    'https://api.flakehub.com/f/pinned/DeterminateSystems/nix-src/3.8.0/0197f52d-2e82-7dec-bad5-e4a6a9b58117/source.tar.gz?narHash=sha256-TgalmClySAhVWpHMmi%2BpAt04w%2B2UPqrWptdqr29iyWo%3D' (2025-07-10)
  → 'https://api.flakehub.com/f/pinned/DeterminateSystems/nix-src/3.8.1/0197fbf2-ebbe-7f60-a1fb-f508f805a6e7/source.tar.gz?narHash=sha256-eb8ZxPP%2BrpuFBce31k/wC6rvvbm7brx/0t9zkC88tMA%3D' (2025-07-11)

* Set Cargo.toml package.version to 3.8.1

---------

Co-authored-by: github-actions[bot] <41898282+github-actions[bot]@users.noreply.github.com>

Author: github-actions[bot]

Cargo.lock

@@ -1,7 +1,7 @@
 [package]
 name = "nix-installer"
 description = "The Determinate Nix Installer"
-version = "3.8.0"
+version = "3.8.1"
 edition = "2021"
 resolver = "2"
 license = "LGPL-2.1"

Cargo.toml

@@ -1,5 +1,5 @@
 {
-  "version": "3.8.0",
+  "version": "3.8.1",
   "actions": [
     {
       "action": {

flake.lock

@@ -1,5 +1,5 @@
 {
-  "version": "3.8.0",
+  "version": "3.8.1",
   "actions": [
     {
       "action": {

tests/fixtures/linux/linux.json

@@ -1,5 +1,5 @@
 {
-  "version": "3.8.0",
+  "version": "3.8.1",
   "actions": [
     {
       "action": {