build, refactor: Reuse expat package version in its download path

Author: hebasto

depends/packages/expat.mk

@@ -1,6 +1,6 @@
 package=expat
 $(package)_version=2.4.1
-$(package)_download_path=https://github.com/libexpat/libexpat/releases/download/R_2_4_1/
+$(package)_download_path=https://github.com/libexpat/libexpat/releases/download/R_$(subst .,_,$($(package)_version))/
 $(package)_file_name=$(package)-$($(package)_version).tar.xz
 $(package)_sha256_hash=cf032d0dba9b928636548e32b327a2d66b1aab63c4f4a13dd132c2d1d2f2fb6a