CI mac: pkgconf/pkg-config problem fix

THe problem seems to be that there is preinstalled pkg-config is CI but
the version that is being to be installed is alias for pkgconf.

.github/scripts/macOS/prepare.sh

@@ -31,14 +31,9 @@ echo "PKG_CONFIG_PATH=/usr/local/lib/pkgconfig" >> "$GITHUB_ENV"
 echo "/usr/local/opt/qt/bin" >> "$GITHUB_PATH"
 echo "DYLIBBUNDLER_FLAGS=$DYLIBBUNDLER_FLAGS" >> "$GITHUB_ENV"
 
-# Ensure that pkg-config is installed but unlinked.
-# This is to prevent interference with pkgconf - both can be installed as
-# a dependency of other packages so ensure a defined state (both installed;
-# pkgconf installed and enabled later).
-if ! brew list pkg-config 2>/dev/null; then
-        brew install pkg-config
+if ! brew list pkgconf 2>/dev/null && ! brew list pkg-config 2>/dev/null; then
+        brew install pkgconf
 fi
-brew unlink pkg-config
 
 set -- \
         asciidoctor \
@@ -55,7 +50,6 @@ set -- \
         molten-vk \
         opencv \
         ossp-uuid `#for cineform` \
-        pkgconf \
         portaudio \
         qt \
         sdl2 \