CI/MacOS: move some things out of the run script into the env key
diff --git a/.github/workflows/macos.yml b/.github/workflows/macos.yml
index 772d4ff..0e68d24 100644
--- a/.github/workflows/macos.yml
+++ b/.github/workflows/macos.yml
@@ -105,13 +105,13 @@
         CPPFLAGS: "-I/opt/homebrew/include"
         LDFLAGS: "-L/opt/homebrew/lib"
         MESON_ARGS: --unity=${{ matrix.unity }}
+        XML_CATALOG_FILES: "/opt/homebrew/etc/xml/catalog"
         CI: 1
         # These cannot evaluate anything, so we cannot set PATH or SDKROOT here
       run: |
         export SDKROOT="$(xcodebuild -version -sdk macosx Path)"
         export PATH="$HOME/tools:/opt/homebrew/opt/qt@5/bin:/opt/homebrew/opt/llvm/bin:/opt/homebrew/opt/ncurses/bin:$PATH"
         export PKG_CONFIG_PATH="/opt/homebrew/opt/qt@5/lib/pkgconfig:/opt/homebrew/opt/lapack/lib/pkgconfig:/opt/homebrew/opt/ncurses/lib/pkgconfig:$PKG_CONFIG_PATH"
-        export XML_CATALOG_FILES="/opt/homebrew/etc/xml/catalog"
         ./tools/run_with_cov.py ./run_project_tests.py --backend=ninja
 
     - name: Aggregate coverage reports