workflows/dispatch-rebottle: support formulae with arm64 Linux bottles

This will allow the `dispatch-rebottle.yml` workflow to just work for
formulae with `:arm64_linux` bottles.

Author: carlocab

Diff for: .github/workflows/dispatch-rebottle.yml

@@ -47,6 +47,7 @@ env:
   HOMEBREW_NO_AUTO_UPDATE: 1
   HOMEBREW_NO_INSTALL_FROM_API: 1
   HOMEBREW_NO_BUILD_ERROR_ISSUES: 1
+  HOMEBREW_ARM64_TESTING: 1
   RUN_URL: ${{github.event.repository.html_url}}/actions/runs/${{github.run_id}}
   DISPATCH_REBOTTLE_SENDER: ${{ github.event.sender.login }}
   DISPATCH_REBOTTLE_FORMULA: ${{ inputs.formula }}

Diff for: cmd/determine-rebottle-runners.rb

@@ -19,24 +19,32 @@ class DetermineRebottleRunnersCmd < AbstractCommand
         hide_from_man_page!
       end
 
-      sig { override.void }
-      def run
-        formula = Formula[T.must(args.named.first)]
-        timeout = args.named.second.to_i
-
-        linux_runner = if timeout > 360
+      sig { params(arch: Symbol, timeout: Integer).returns(T::Hash[Symbol, T.any(String, T::Hash[Symbol, String])]) }
+      def linux_runner_spec(arch, timeout)
+        linux_runner = if arch == :arm64
+          "ubuntu-22.04-arm"
+        elsif timeout > 360
           "linux-self-hosted-1"
         else
           "ubuntu-latest"
         end
-        linux_runner_spec = {
+
+        {
           runner:    linux_runner,
           container: {
             image:   "ghcr.io/homebrew/ubuntu22.04:master",
             options: "--user=linuxbrew -e GITHUB_ACTIONS_HOMEBREW_SELF_HOSTED",
           },
           workdir:   "/github/home",
         }
+      end
+
+      KNOWN_LINUX_ARCHES = [:arm64, :x86_64].freeze
+
+      sig { override.void }
+      def run
+        formula = Formula[T.must(args.named.first)]
+        timeout = args.named.second.to_i
 
         tags = formula.bottle_specification.collector.tags
         runners = if tags.count == 1 && tags.first.system == :all
@@ -51,7 +59,7 @@ def run
               macos_runners << { runner: "#{macos_version}-arm64#{ephemeral_suffix}" }
               macos_runners
             end
-          end << linux_runner_spec
+          end << linux_runner_spec(:x86_64, timeout)
         else
           tags.map do |tag|
             macos_version = tag.to_macos_version
@@ -66,8 +74,8 @@ def run
               { runner: }
             end
           rescue MacOSVersion::Error
-            if tag.system == :linux && tag.arch == :x86_64
-              linux_runner_spec
+            if tag.system == :linux && KNOWN_LINUX_ARCHES.include?(tag.arch)
+              linux_runner_spec(tag.arch, timeout)
             elsif tag.system == :all
               # An all bottle with OS-specific bottles also present - ignore it.
               nil