Use uv to manage docs Python dependencies

UV's use of a lockfile makes building the docs more reliable, and it installs the dependencies faster too (though in CI that's largely hidden by having to install Doxygen every time).

.github/workflows/ci.yml

@@ -101,10 +101,14 @@ jobs:
 
       - name: Install packages for building docs
         shell: bash
-        run: pip3 install --user -r docs/requirements.txt
+        working-directory: docs
+        run: |
+          pipx install uv
+          uv sync
 
       - name: Build docs
-        run: sphinx-build -b html docs build/docs/html
+        working-directory: docs
+        run: uv run -- sphinx-build -b html . ../build/docs/html
 
       - name: Build archive
         id: build-archive
@@ -214,10 +218,13 @@ jobs:
 
           echo "${{ github.workspace }}\doxygen-1.13.2.windows.x64.bin" | Out-File -FilePath $env:GITHUB_PATH -Encoding utf8 -Append
 
-          python -m pip install -r docs/requirements.txt
+          pipx install uv
+          cd docs
+          uv sync
 
       - name: Build docs
-        run: sphinx-build -b html docs build\docs\html
+        working-directory: docs
+        run: uv run -- sphinx-build -b html . ../build/docs/html
 
       - name: Build archive
         id: build-archive

.github/workflows/release.yml

@@ -105,10 +105,13 @@ jobs:
 
           echo "${{ github.workspace }}\doxygen-1.13.2.windows.x64.bin" | Out-File -FilePath $env:GITHUB_PATH -Encoding utf8 -Append
 
-          python -m pip install -r docs/requirements.txt
+          pipx install uv
+          cd docs
+          uv sync
 
       - name: Build docs
-        run: sphinx-build -b html docs build\docs\html
+        working-directory: docs
+        run: uv run -- sphinx-build -b html . ../build/docs/html
 
       - name: Build archive
         id: build-archive