CI: remove macos temporary fix

Author: vouillon

.github/workflows/build.yml

@@ -97,14 +97,6 @@ jobs:
           # try to install them anyways, so we save an apt-roundtrip.
           sudo aptitude -o Acquire::Retries=30 install gcc-multilib g++-multilib pkg-config libgmp-dev libgmp-dev:i386 libx11-dev:i386 -y
 
-      - name: macos fix
-        if: runner.os == 'Macos'
-        run: |
-          brew update
-          brew upgrade
-          brew install pkgconf
-          # work around https://github.com/actions/runner-images/issues/10984
-
       - name: Checkout tree
         uses: actions/checkout@v4