Fix the Swift for macOS installer to encode a minimum OS version for installation (#83273)

Right now it defaults to macOS 10.11, which is of course far below the
intended supported version.

Author: jakepetroules

utils/build-script-impl

@@ -3172,7 +3172,7 @@ function build_and_test_installable_package() {
             echo "-- Create Installer --"
             call "${SWIFT_SOURCE_DIR}/utils/toolchain-installer" "${host_install_destdir}${TOOLCHAIN_PREFIX}/" "${DARWIN_TOOLCHAIN_BUNDLE_IDENTIFIER}" \
                 "${DARWIN_TOOLCHAIN_INSTALLER_CERT}" "${DARWIN_TOOLCHAIN_INSTALLER_PACKAGE}" "${DARWIN_TOOLCHAIN_INSTALL_LOCATION}" \
-                "${DARWIN_TOOLCHAIN_VERSION}" "${SWIFT_SOURCE_DIR}/utils/darwin-installer-scripts"
+                "${DARWIN_TOOLCHAIN_VERSION}" "${SWIFT_SOURCE_DIR}/utils/darwin-installer-scripts" "${DARWIN_DEPLOYMENT_VERSION_OSX}"
           fi
 
           # host_install_destdir contains the toolchain prefix.

utils/toolchain-installer

@@ -18,7 +18,8 @@ DARWIN_INSTALLER_PACKAGE=$4
 DARWIN_TOOLCHAIN_INSTALL_LOCATION=$5
 DARWIN_TOOLCHAIN_VERSION=$6
 DARWIN_SCRIPTS=$7
+DARWIN_DEPLOYMENT_VERSION_OSX=$8
 
 pkgbuild --root "${TOOLCHAIN_PREFIX}" --install-location "${DARWIN_TOOLCHAIN_INSTALL_LOCATION}" "${DARWIN_INSTALLER_PACKAGE}" \
          --version "${DARWIN_TOOLCHAIN_VERSION}" --identifier "${DARWIN_BUNDLE_IDENTIFIER}" --sign "${DARWIN_INSTALLER_CERT}" \
-         --scripts "${DARWIN_SCRIPTS}"
+         --scripts "${DARWIN_SCRIPTS}" --min-os-version "${DARWIN_DEPLOYMENT_VERSION_OSX}"