fix(ci): set PYTHON_GIL=0 for pytest in free-threaded builds

Author: shiftinv

pyproject.toml

@@ -174,6 +174,14 @@ before-all = ["./scripts/setup-vcpkg.sh"]
 select = "*linux_{aarch64,armv7l,ppc64le,s390x,riscv64}"
 environment = { VCPKG_FORCE_SYSTEM_BINARIES = "1" }
 
+# While this doesn't actually support free-threading just yet, we build wheels for it nonetheless,
+# even if it results in the GIL being re-enabled on import, just so they're available.
+# This results in a RuntimeWarning, which makes tests fail, so explicitly disable the
+# GIL for tests to avoid the warning.
+[[tool.cibuildwheel.overrides]]
+select = "cp*t-"
+test-environment = { PYTHON_GIL = "0" }
+
 
 # Needed for full C++17 support on macOS
 [tool.cibuildwheel.macos.environment]