chore(goreleaser): use binaries field in homebrew

Replace deprecated binary field with binaries array syntax in
homebrew_casks configuration to resolve GoReleaser deprecation
warning.

Signed-off-by: Akshay Pant <akshay.akshaypant@gmail.com>

Author: theakshaypant

.goreleaser.yml

@@ -86,7 +86,7 @@ homebrew_casks:
       - formula: git
     homepage: "https://pipelinesascode.com"
     description: tkn-pac - A command line interface for interacting with Pipelines as Code
-    binary: "tkn-pac"
+    binaries: ["tkn-pac"]
     custom_block: |
       zsh_completion = "#{staged_path}/_tkn-pac"
       bash_completion = "#{staged_path}/tkn-pac.bash"