Install fontforge pkg from community branch

The Alpine Linux package repository no longer contains the `fontforge` package for x86 and ARM architectures in the `edge/testing` branch.

This commit updates the Dockerfile to install the `fontforge` package from the `edge/community` branch to resolve the failing Docker builds.

Dockerfile

@@ -6,7 +6,7 @@ LABEL org.opencontainers.image.title="Nerd Fonts Patcher" \
       org.opencontainers.image.source="https://github.com/ryanoasis/nerd-fonts" \
       org.opencontainers.image.licenses="MIT"
 
-RUN apk update && apk upgrade && apk add --no-cache fontforge --repository=https://dl-cdn.alpinelinux.org/alpine/edge/testing && \
+RUN apk update && apk upgrade && apk add --no-cache fontforge --repository=https://dl-cdn.alpinelinux.org/alpine/edge/community && \
     apk add --no-cache py3-pip && \
     pip install configparser