Move away from reliance on DYLD_LIBRARY_PATH

With the introduction of macOS System Integrity Protect (SIP)
LD_LIBRARY_PATH and DYLD_LIBRARY_PATH environment variables may be
stripped before execution.  See:

 * https://help.mulesoft.com/s/article/Variables-LD-LIBRARY-PATH-DYLD-LIBRARY-PATH-are-ignored-on-MAC-OS-if-System-Integrity-Protect-SIP-is-enable

.github/workflows/native.yml

@@ -88,11 +88,13 @@ jobs:
         run: brew install swig
 
       - name: Build native code
-        run: make clean swig all
+        run: |
+          make clean swig all
+          mkdir -p ${HOME}/Library/Java/Extensions
+          cp build/*.dylib ${HOME}/Library/Java/Extensions
 
       - name: Run tests
         run: |
-          export DYLD_LIBRARY_PATH=${GITHUB_WORKSPACE}/build
           cd build
           mkdir -p transcoded/C/ transcoded/C++/ transcoded/Java/
           # Test base jxrlib C library