Fixup: fix setting LLVM_VERSION for the host and cibuildwheel envs

Author: ggeorgakoudis

.github/workflows/build-upload-wheels.yml

@@ -38,11 +38,11 @@ jobs:
         run: python -m pip install cibuildwheel==3.1.4
 
       - name: Build wheels {{ matrix.os }}
+        # Set LLVM_VERSION for the host and cibuildwheel environment.
         env:
           LLVM_VERSION: "15.0.7"
-        run: |
-          python -m cibuildwheel --output-dir wheelhouse
-
+          CIBW_ENVIRONMENT: "LLVM_VERSION=15.0.7"
+        run: python -m cibuildwheel --output-dir wheelhouse
 
       - uses: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02
         with:
@@ -57,6 +57,8 @@ jobs:
           fetch-depth: 0
 
       - name: Build sdist
+        env:
+          LLVM_VERSION: "15.0.7"
         run: pipx run build --sdist
 
       - uses: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02