fix(homebrew): clear rubocop offenses on formula (#967)

fix(homebrew): clear two rubocop offenses

brew style on homebrew-core surfaced two offenses on the formula
copy that landed in main with PR #904:

- Layout/ExtraSpacing: double space before => in uses_from_macos
- Style/FileNull: use File::NULL instead of "/dev/null"

Mirror the same fixes already applied to the upstream PR
(Homebrew/homebrew-core#283241).

Formula/kandev.rb

@@ -14,7 +14,7 @@ class Kandev < Formula
   depends_on "pnpm" => :build
   depends_on "node"
 
-  uses_from_macos "rsync"  => :build
+  uses_from_macos "rsync" => :build
   uses_from_macos "sqlite"
 
   def install
@@ -64,7 +64,7 @@ class Kandev < Formula
                 libexec/"bin/kandev")
     begin
       deadline = Time.now + 60
-      until system("curl", "-sf", "-o", "/dev/null",
+      until system("curl", "-sf", "-o", File::NULL,
                    "http://127.0.0.1:#{port}/api/v1/system/health")
         raise "kandev backend did not start within 60s" if Time.now > deadline