Limit setuptools versions as required for llvmlite wheel building

Author: ggeorgakoudis

pyproject.toml

@@ -51,6 +51,9 @@ environment-pass = ["LLVM_VERSION"]
 # We use miniconda3 to get the clang/llvm toolchain on Linux.
 before-build = ["rm -rf build dist src/*.egg-info"]
 skip = ["*-musllinux_*", "cp38-*"]
+# llvmlite needs setuptools < 82, and we may need to build from source, so we
+# ensure that setuptools is in the correct version range.
+test-requires = ["setuptools>=75.3,<82"]
 test-command = [
     # Run host OpenMP tests.
     "TEST_DEVICES=0 RUN_TARGET=0 python -m numba.runtests -v -- numba.openmp.tests.test_openmp",