feat: add branch param

Library/Homebrew/dev-cmd/pr-publish.rb

@@ -19,6 +19,8 @@ module Homebrew
       switch "--autosquash",
              description: "If supported on the target tap, automatically reformat and reword commits "\
                           "in the pull request to our preferred format."
+      flag   "--branch=",
+             description: "Branch to publish (default: `master`)."
       flag   "--message=",
              depends_on:  "--autosquash",
              description: "Message to include when autosquashing revision bumps, deletions, and rebuilds."
@@ -36,7 +38,7 @@ module Homebrew
 
     tap = Tap.fetch(args.tap || CoreTap.instance.name)
     workflow = args.workflow || "publish-commit-bottles.yml"
-    ref = "master"
+    ref = args.branch || "master"
 
     extra_args = []
     extra_args << "--autosquash" if args.autosquash?