GoReleaser: Switch to `homebrew_casks` from `brews`

[tangrufus]

GoReleaser has deprecated brews since v2.10 (June 8, 2025). We should switch to homebrew_casks.

See: https://goreleaser.com/blog/goreleaser-v2.10/

trellis-cli/.goreleaser.yml

Lines 40 to 52 in 546bc54

	brews:
	- name: trellis-cli
	repository:
	owner: roots
	name: homebrew-tap
	directory: Formula
	homepage: https://roots.io/trellis
	description: A CLI to manage Trellis projects
	install: |
	bin.install "trellis"
	test: |
	system "#{bin}/trellis --autocomplete-install"
	system "#{bin}/trellis -v"

[swalkinshaw]

Want to do a PR? I guess it's just a simple update?