Since the setting DCMAKE_SKIP_BUILD_RPATH was disabled, we can now run
the checkPhase of cmake derivations without having to tweak the
LD_LIBRARY_PATH anymore.
This fixes the LibraryCLinkageTest, which was failing to find the built library:
1122/1129 Test #1128: LibraryCLinkageTest .......................................................................................................Subprocess aborted***Exception: 0.32 sec
dyld[53579]: Library not loaded: @rpath/libjxl.0.dylib
Referenced from: /private/tmp/nix-build-libjxl-0.5.drv-1/source/build/tools/tests/libjxl_test
Reason: tried: '/nix/store/82d092jfk2sckailcp5hpb29xsxhk4h2-swift-corefoundation/Library/Frameworks/libjxl.0.dylib' (no such file), '/nix/store/82d092jfk2sckailcp5hpb29xsxhk4h2-swift-corefoundation/Library/Frameworks/libjxl.0.dylib' (no
