Use REUSE to validate presence of file copyrights and licenses in CI

.github/workflows/test-exercises.yml

@@ -15,6 +15,18 @@ concurrency:
   cancel-in-progress: true
 
 jobs:
+  verify-licenses:
+    runs-on: ubuntu-latest
+    name: Validate that all files have copyright and license info
+    steps:
+      - uses: actions/checkout@v6
+      - name: Install REUSE
+        run: |
+          ./CI/setup-uv.sh
+          uv pip install reuse
+      - name: Validate presence of copyright and license info (python w/reuse)
+        run: |
+          uv run reuse lint
   test-exercise:
     timeout-minutes: 30   
     runs-on: ubuntu-latest

CI/setup-uv.sh

@@ -0,0 +1,16 @@
+#! /bin/bash
+
+# SPDX-FileCopyrightText: 2026 Andy Fingerhut
+#
+# SPDX-License-Identifier: Apache-2.0
+
+sudo apt-get update
+# Set up uv for Python dependency management.
+# TODO: Consider using a system-provided package here.
+sudo apt-get install -y curl
+curl -LsSf https://astral.sh/uv/0.6.12/install.sh | sh
+# Ensure uv is in the PATH
+export PATH="${PATH}:$HOME/.local/bin"
+# Create a venv for use by uv, without needing a pyproject.toml file for the project.
+uv venv
+uv tool update-shell