feat: add alpine 3.21, build on AX42

builder/package.alpine-321

@@ -0,0 +1,74 @@
+#!/bin/bash
+
+if [[ ! -d /tmp/output/${OS_IDENTIFIER} ]]; then
+  mkdir -p "/tmp/output/${OS_IDENTIFIER}"
+fi
+
+# R 3.x requires PCRE1. On Ubuntu 24, R 3.x also requires PCRE2 for Pango support.
+pcre_libs='- pcre2-dev'
+if [[ "${R_VERSION}" =~ ^3 ]]; then
+  pcre_libs='- pcre2-dev
+- libpcre3-dev'
+fi
+
+deflate_libs='# - libdeflate-dev'
+if grep -q '^LIBS *=.*[-]ldeflate' ${R_INSTALL_PATH}/lib/R/etc/Makeconf; then
+    deflate_libs='- libdeflate-dev'
+fi
+
+cat <<EOF > /tmp/nfpm.yml
+name: r-${R_VERSION}
+version: 1
+version_schema: none
+section: universe/math
+priority: optional
+arch: $(arch)
+maintainer: Posit Software, PBC <https://github.com/rstudio/r-builds>
+description: |
+  GNU R statistical computation and graphics system
+vendor: Posit Software, PBC
+homepage: https://www.r-project.org
+license: GPL-2
+depends:
+- g++
+- gcc
+- gfortran
+- libbz2
+# - libc6
+- cairo
+- libcurl
+${deflate_libs}
+# - libglib2.0-0t64
+# - libgomp1
+- icu-dev
+- jpeg-dev
+# - liblzma-dev
+- openblas-dev
+- pango
+# - libpangocairo-1.0-0
+- libpaper
+${pcre_libs}
+- libpng-dev
+- readline-dev
+- tcl
+- tiff-dev
+- libtirpc-dev
+- tk
+# - libx11-6
+# - libxt6t64
+- make
+# - ucf
+- unzip
+- zip
+- zlib-ng-dev
+contents:
+- src: ${R_INSTALL_PATH}
+  dst: ${R_INSTALL_PATH}
+EOF
+
+nfpm package \
+  -f /tmp/nfpm.yml \
+  -p apk \
+  -t "/tmp/output/${OS_IDENTIFIER}"
+
+export PKG_FILE=$(ls /tmp/output/${OS_IDENTIFIER}/r-${R_VERSION}*.apk | head -1)