Update lint workflow to use uv for dependencies

Author: jb3

.github/workflows/lint-test.yaml

@@ -8,11 +8,15 @@ jobs:
     name: Run linting & tests
     runs-on: ubuntu-latest
     steps:
-      - name: Install Python Dependencies
-        uses: HassanAbouelela/actions/setup-python@setup-python_v1.6.0
+      - name: Install uv
+        uses: astral-sh/setup-uv@v6
         with:
-          python_version: '3.12'
-          install_args: "--only main --only lint --only test"
+          enable-cache: true
+          cache-dependency-glob: "uv.lock"
+          activate-environment: true
+
+      - name: Install dependencies
+        run: uv sync --frozen --group lint --group test
 
       # Attempt to run the bot. Setting `IN_CI` to true, so bot.run() is never called.
       # This is to catch import and cog setup errors that may appear in PRs, to avoid crash loops if merged.