Revert "ci: Skip GTK4 on macOS 12 temporarily"

This reverts commit 7ac8eee.

Author: QuLogic

.github/workflows/tests.yml

@@ -159,12 +159,7 @@ jobs:
           macOS)
             brew update
             export HOMEBREW_NO_INSTALL_UPGRADE=1 HOMEBREW_NO_INSTALLED_DEPENDENTS_CHECK=1
-            brew install ccache ghostscript ninja
-            # The macOS 12 images have an older Python, and this causes homebrew to generate conflicts.
-            # We'll just skip GTK for now, to not pull in Python updates.
-            if [[ "${{ matrix.os }}" = macos-14 ]]; then
-              brew install gobject-introspection gtk4
-            fi
+            brew install ccache ghostscript gobject-introspection gtk4 ninja
             brew install --cask font-noto-sans-cjk inkscape
             ;;
           esac