utils/github: remove unnecessary chdir call

The only existing caller already has the requested directory as the
workign directory, so this is currently not needed.

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

@@ -482,7 +482,7 @@ module Homebrew
 
             ohai "Downloading bottles for workflow: #{workflow}"
             url = GitHub.get_artifact_url(workflow_run)
-            GitHub.download_artifact(url, pr, dir)
+            GitHub.download_artifact(url, pr)
           end
 
           next if args.no_upload?

Library/Homebrew/utils/github.rb

@@ -372,7 +372,14 @@ module GitHub
     artifact.last["archive_download_url"]
   end
 
-  def self.download_artifact(url, artifact_id, dir = Pathname.pwd)
+  # Downloads an artifact from GitHub Actions.
+  #
+  # @param url [String] URL to download from
+  # @param artifact_id [String] a value that uniquely identifies the downloaded artifact
+  #
+  # @api private
+  sig { params(url: String, artifact_id: String).void }
+  def self.download_artifact(url, artifact_id)
     odie "Credentials must be set to access the Artifacts API" if API.credentials_type == :none
 
     token = API.credentials
@@ -381,17 +388,15 @@ module GitHub
     # Download the artifact as a zip file and unpack it into `dir`. This is
     # preferred over system `curl` and `tar` as this leverages the Homebrew
     # cache to avoid repeated downloads of (possibly large) bottles.
-    FileUtils.chdir dir do
-      downloader = GitHubArtifactDownloadStrategy.new(
-        url,
-        "artifact",
-        artifact_id,
-        curl_args: curl_args,
-        secrets:   [token],
-      )
-      downloader.fetch
-      downloader.stage
-    end
+    downloader = GitHubArtifactDownloadStrategy.new(
+      url,
+      "artifact",
+      artifact_id,
+      curl_args: curl_args,
+      secrets:   [token],
+    )
+    downloader.fetch
+    downloader.stage
   end
 
   def self.public_member_usernames(org, per_page: 100)