Avoid confusing PIP_NO_BUILD_ISOLATION

The latest version of `cibuildwheel` allows passing arguments directly
to the build frontend CLI.

Author: abravalheri

.github/workflows/ci.yml

@@ -312,18 +312,15 @@ jobs:
       - uses: dtolnay/rust-toolchain@stable
         with:
           targets: aarch64-apple-darwin
-      - uses: pypa/cibuildwheel@v2.3.1
+      - uses: pypa/cibuildwheel@v2.16.2
         env:
           CIBW_BUILD: cp39-*
           CIBW_BEFORE_BUILD: pip install -U 'pip>=23.2.1' 'setuptools>=68.0.0' 'wheel<=0.37.1' && pip install -e . && pip list
           # ^-- cap on `wheel` is a workaround for pypa/auditwheel#436
           #     setuptools needs to be upgraded before installing setuptools-rust
           CIBW_ARCHS_MACOS: "x86_64 universal2 arm64"
           CIBW_BUILD_VERBOSITY: 3
-          CIBW_BUILD_FRONTEND: pip  # pip allows disabling isolation via env var
-          CIBW_ENVIRONMENT: PIP_NO_BUILD_ISOLATION=false
-          # ^-- necessary to use working copy of setuptools-rust,
-          #     (however PIP_NO_BUILD_ISOLATION is counter-intuitive: see pypa/pip#5735)
+          CIBW_BUILD_FRONTEND: "build; args: --no-isolation"
         with:
           package-dir: examples/namespace_package