CI: Fix release workflow

[why]
Release workflow for 2.3.0 stopped.
The script generate-webfonts.sh needs fontforge which was not installed.

[how]
Install the (ordinary) fontforge. As we just export the woff we can live
with whatever version is available.

Signed-off-by: Fini Jastrow <ulf.fini.jastrow@desy.de>

.github/workflows/release.yml

@@ -335,6 +335,8 @@ jobs:
 
       - name: Generate new CSS file and webfonts
         run: |
+          sudo apt update -y -q
+          sudo apt install fontforge -y -q
           cd -- "$GITHUB_WORKSPACE/bin/scripts"
           ./generate-css.sh
           ./generate-webfonts.sh