[Fix] Add libxrender, libxext6 and libfontconfig1 libs to envipy image (#278)

Co-authored-by: Tim Lorsbach <tim@lorsba.ch>
Reviewed-on: enviPath/enviPy#278

.gitea/docker/Dockerfile.ci

@@ -19,6 +19,9 @@ RUN apt-get update && \
       lsb-release \
       git \
       ssh \
+      libxrender1 \
+      libxext6 \
+      libfontconfig1 \
       && rm -rf /var/lib/apt/lists/*
 
 # Install Node.js 24 via NodeSource