fix(zlib)

llvm17 breaks shlib support. this fixes that.

projects/zlib.net/package.yml

@@ -10,8 +10,11 @@ build:
     ./configure --prefix="{{prefix}}"
     make --jobs {{ hw.concurrency }} install
   env:
-    linux/aarch64:
-      CFLAGS: '$CFLAGS -fPIC'
+    linux:
+      CFLAGS:
+        - -fPIC
+        # undefined symbol errors in newer llvms prevent building shared libs
+        - -Wl,--undefined-version
 
 test:
   script: |