try to install firefox only when actually running selenium tests

Author: mathiasertl

.github/workflows/tests.yml

@@ -20,7 +20,11 @@ jobs:
     name: Python ${{ matrix.python-version }}, Django ${{ matrix.django-version }}, cryptography ${{ matrix.cryptography-version }}, pydantic ${{ matrix.pydantic-version }}
     steps:
       - name: Install APT dependencies
-        run: sudo apt-get install -y firefox softhsm2
+        run: sudo apt-get install -y softhsm2
+
+      - name: Install Firefox
+        run: sudo apt-get install -y firefox
+        if: ${{ matrix.python-version == '3.13' && matrix.cryptography-version == '44.0' && matrix.pydantic-version == '2.10.0' }}
 
       - name: Acquire sources
         uses: actions/checkout@v4.1.1