ci: prevent libpq auto-upgrade with HOMEBREW_NO_INSTALL_UPGRADE

Author: datlechin

.github/workflows/build.yml

@@ -64,7 +64,7 @@ jobs:
           # uses strchrnul (26.0-only) → crash at launch on older macOS.
           if ! brew list libpq &>/dev/null; then
             echo "📦 Installing libpq (from source, targeting macOS 14.0)..."
-            HOMEBREW_MACOS_DEPLOYMENT_TARGET=14.0 brew install --build-from-source libpq
+            HOMEBREW_MACOS_DEPLOYMENT_TARGET=14.0 HOMEBREW_NO_INSTALL_UPGRADE=1 brew install --build-from-source libpq
           else
             echo "✅ libpq already installed"
           fi
@@ -321,7 +321,7 @@ jobs:
           # uses strchrnul (26.0-only) → crash at launch on older macOS.
           if ! arch -x86_64 /usr/local/bin/brew list libpq &>/dev/null; then
             echo "📦 Installing libpq (x86_64, from source, targeting macOS 14.0)..."
-            arch -x86_64 env HOMEBREW_MACOS_DEPLOYMENT_TARGET=14.0 /usr/local/bin/brew install --build-from-source libpq
+            arch -x86_64 env HOMEBREW_MACOS_DEPLOYMENT_TARGET=14.0 HOMEBREW_NO_INSTALL_UPGRADE=1 /usr/local/bin/brew install --build-from-source libpq
           else
             echo "✅ libpq (x86_64) already installed"
           fi