CI: Replace deprecated macos-12 runner by macos-14 runner

Homebrew no longer supports macOS 12.

The update fixes these CI annotations:

A brownout will take place on November 4, 14:00 UTC - November 5, 00:00 UTC
to raise awareness of the upcoming macOS-12 environment removal. For more
details, see actions/runner-images#10721

You are using macOS 12.
We (and Apple) do not provide support for this old version.

Fix also another CI annotation:

HOMEBREW_NO_INSTALLED_DEPENDENTS_CHECK is set:
not checking for outdated dependents or dependents with broken linkage!

Fixes: #762
Signed-off-by: Stefan Weil <[email protected]>

.github/workflows/autotools-macos.yml

@@ -26,8 +26,8 @@ jobs:
       fail-fast: false
       matrix:
         config:
-          - { os: macos-12, cc: clang }
           - { os: macos-13, cc: clang }
+          - { os: macos-14, cc: clang }
 
     steps:
     - uses: actions/checkout@v4
@@ -37,15 +37,9 @@ jobs:
            ${{ matrix.config.cc }} --version
            git log -3 --pretty=format:'%h %ad %s | %an'
 
-    - name: Clean Homebrew installation
-      run: |
-           brew uninstall aws-sam-cli azure-cli bazelisk
-           brew uninstall geckodriver firefox google-chrome microsoft-edge
-           brew info python3
-
     - name: Install dependencies
       run: |
-           brew install automake gnuplot || true
+           brew install automake gnuplot libtool || true
 
     - name: Setup Leptonica
       run: |