Optimized Docker build to fix OOM errors

Dockerfile

@@ -17,7 +17,7 @@ ENV MAX_JOBS=1
 RUN git clone --depth 1 https://github.com/NVlabs/nvdiffrast.git /tmp/nvdiffrast \
     && cd /tmp/nvdiffrast \
     && python3 setup.py build_ext --inplace
-RUN python3 -c "import shutil, sysconfig, glob; from pathlib import Path; site=Path(sysconfig.get_paths()['purelib']); src=Path('/tmp/nvdiffrast/nvdiffrast'); dst=site/'nvdiffrast'; shutil.rmtree(dst, ignore_errors=True); shutil.copytree(src, dst); so_files=glob.glob('/tmp/nvdiffrast/_nvdiffrast_c*.so'); [shutil.copy2(p, site) for p in so_files]"
+RUN python3 -c "import shutil, sysconfig, glob; from pathlib import Path; site=Path(sysconfig.get_paths()['purelib']); src=Path('/tmp/nvdiffrast/nvdiffrast'); dst=site/'nvdiffrast'; shutil.rmtree(dst, ignore_errors=True); shutil.copytree(src, dst); so_files=(glob.glob('/tmp/nvdiffrast/_nvdiffrast_c*.so') + glob.glob('/tmp/nvdiffrast/nvdiffrast/_nvdiffrast_c*.so') + glob.glob('/tmp/nvdiffrast/build/lib.*/*_nvdiffrast_c*.so')); [shutil.copy2(p, site) for p in so_files]"
 RUN python3 -c "import sysconfig; from pathlib import Path; site=Path(sysconfig.get_paths()['purelib']); dist=site/'nvdiffrast-0.0.0.dist-info'; dist.mkdir(exist_ok=True); (dist/'METADATA').write_text('Metadata-Version: 2.1\\nName: nvdiffrast\\nVersion: 0.0.0\\n'); (dist/'WHEEL').write_text('Wheel-Version: 1.0\\nGenerator: manual\\nRoot-Is-Purelib: false\\nTag: py3-none-any\\n'); (dist/'top_level.txt').write_text('nvdiffrast\\n'); (dist/'RECORD').write_text('')"
 RUN python3 -c "import nvdiffrast.torch"
 RUN rm -rf /tmp/nvdiffrast