github build: Add ImageMagick to workflow (#138)

* Add ImageMagick to build workflow

Required for ubuntu-24.04 which no longer includes it

Author: mreid-tt

Diff for: .github/workflows/build.yml

@@ -25,6 +25,8 @@ jobs:
       - uses: snok/install-poetry@v1
         with:
           virtualenvs-in-project: true
+      - name: Install ImageMagick
+        run: sudo apt install imagemagick
       - name: Load cached venv
         id: cached-poetry-dependencies
         uses: actions/cache@v4