Merge branch 'sg/ci-brew-gcc-workaround' into next

Dev support update.

* sg/ci-brew-gcc-workaround:
  ci: disable Homebrew's auto cleanup
  ci: don't update Homebrew

Author: gitster

ci/install-dependencies.sh

@@ -34,7 +34,7 @@ linux-clang|linux-gcc)
 	popd
 	;;
 osx-clang|osx-gcc)
-	brew update >/dev/null
+	export HOMEBREW_NO_AUTO_UPDATE=1 HOMEBREW_NO_INSTALL_CLEANUP=1
 	# Uncomment this if you want to run perf tests:
 	# brew install gnu-time
 	test -z "$BREW_INSTALL_PACKAGES" ||