ci: Add macOS support to install-deps.sh

Use brew install --quiet to suppress warnings about already-installed
packages on the GitHub Actions runner.

Assisted-by: Claude:claude-opus-4-6
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

.github/workflows/build.yml

@@ -89,7 +89,7 @@ jobs:
 
       - name: Install Dependencies
         run: |
-          brew install libyaml swig meson ninja pkg-config
+          ./scripts/install-deps.sh
 
       - name: Build (Make)
         if: matrix.build == 'make'

scripts/install-deps.sh

@@ -1,6 +1,12 @@
 #!/bin/sh
 # SPDX-License-Identifier: GPL-2.0-or-later
 
+if [ "$(uname -s)" = "Darwin" ]
+then
+    brew install --quiet libyaml swig meson ninja pkg-config
+    exit 0
+fi
+
 if [ "$(uname -s)" = "FreeBSD" ]
 then
     pkg install -y git gmake flex bison meson ninja \