Vendor the correct liblz4 into macOS wheels

We were previously setting `DYLD_LIBRARY_PATH`, but macOS's System
Integrity Protections were resulting in that environment being dropped
before `delocate` was run, causing an incorrect version of `liblz4` to
be found and vendored.

See pypa/cibuildwheel#816

Signed-off-by: Matt Wozniski <godlygeek@gmail.com>

.github/workflows/build_wheels.yml

@@ -163,7 +163,7 @@ jobs:
           CIBW_BUILD_VERBOSITY: 1
           CFLAGS: "${{env.CFLAGS}} -I${{env.LZ4_INSTALL_DIR}}/include"
           LDFLAGS: "-L${{env.LZ4_INSTALL_DIR}}/lib -Wl,-rpath,${{env.LZ4_INSTALL_DIR}}/lib"
-          DYLD_LIBRARY_PATH: "${{env.LZ4_INSTALL_DIR}}/lib"
+          PKG_CONFIG_PATH: "${{env.LZ4_INSTALL_DIR}}/lib/pkgconfig"
       - uses: actions/upload-artifact@v4
         with:
           name: macosx_${{ matrix.arch }}-wheels

pyproject.toml

@@ -83,7 +83,8 @@ before-all = [
   "git clone --depth 1 --branch v1.9.4 https://github.com/lz4/lz4 lz4",
   "cd lz4",
   "make",
-  "make install PREFIX=$LZ4_INSTALL_DIR"
+  "make install PREFIX=$LZ4_INSTALL_DIR",
+  "find $LZ4_INSTALL_DIR",
 ]
 before-test = [
   "codesign --remove-signature /Library/Frameworks/Python.framework/Versions/*/bin/python3 || true",