Try using the HTTP URL to see if it fixes the build

Author: mnapoli

php-80/Dockerfile

@@ -80,7 +80,7 @@ ENV VERSION_ZLIB=1.3
 ENV ZLIB_BUILD_DIR=${BUILD_DIR}/zlib
 RUN set -xe; \
     mkdir -p ${ZLIB_BUILD_DIR}; \
-    curl -Ls https://zlib.net/zlib-${VERSION_ZLIB}.tar.xz \
+    curl -Ls http://zlib.net/zlib-${VERSION_ZLIB}.tar.xz \
   | tar xJC ${ZLIB_BUILD_DIR} --strip-components=1
 WORKDIR ${ZLIB_BUILD_DIR}/
 RUN set -xe; \