fix: add libgfortran5 to Docker runtime stage for DAlphaBall

The DAlphaBall.gcc binary requires libgfortran.so.5 on the system
library path. It was only installed in the conda env (builder stage),
which system binaries cannot access, causing PyRosetta scoring to crash.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: xux

Dockerfile

@@ -56,7 +56,7 @@ RUN conda clean -a -y
 FROM continuumio/miniconda3:24.7.1-0 AS runtime
 
 RUN apt-get update && apt-get install -y \
-    libgomp1 git wget \
+    libgomp1 libgfortran5 git wget \
     && rm -rf /var/lib/apt/lists/*
 
 WORKDIR /app