Don't install a system-wide lpeg

Pandoc now relies on the version that's compiled-in.

Author: tarleb

alpine/Dockerfile

@@ -87,8 +87,7 @@ RUN ln -s /usr/local/bin/pandoc /usr/local/bin/pandoc-lua && \
     apk --no-cache add \
     gmp \
     libffi \
-    lua$lua_version \
-    lua$lua_version-lpeg
+    lua$lua_version
 
 # Core ##################################################################
 FROM alpine-minimal AS alpine-core

ubuntu/Dockerfile

@@ -91,7 +91,6 @@ RUN ln -s /usr/local/bin/pandoc /usr/local/bin/pandoc-lua \
      apt-get install --assume-yes --no-install-recommends \
        ca-certificates=\* \
        liblua$lua_version-0=\* \
-       lua-lpeg=\* \
        libatomic1=\* \
        libgmp10=\* \
        libpcre3=\* \