Fix GoReleaser homebrew publish to actually use the PR flow

The brew publish on v0.0.1-beta failed because GoReleaser was trying
to push the formula directly to homebrew-tap's `main` branch (blocked
by branch protection), then attempted a fork-sync (no fork exists),
then gave up.

Two config bugs:

1. `repository.branch` wasn't set, so GoReleaser defaulted to `main`
   and pushed there instead of creating a feature branch. Set it to
   `band-{{.Version}}` so each release gets its own branch.
2. `pull_request.base.owner` and `base.name` were set to the same
   values as `repository.owner/name`, which makes GoReleaser think
   this is a cross-repo (fork-based) PR flow. Remove them — when
   only `base.branch` is set, GoReleaser uses the same-repo
   branch-and-PR flow, which is what we want here.

Also name the formula `band.rb` explicitly (via `brews[].name: band`)
so `brew install Bandwidth/tap/band` resolves — the default was
`cli.rb` (after the repo name), which didn't match the binary name.

Author: kshahbw

.goreleaser.yml

@@ -52,15 +52,15 @@ docker_manifests:
       - "ghcr.io/bandwidth/cli:{{ .Version }}-arm64"
 
 brews:
-  - repository:
+  - name: band
+    repository:
       owner: Bandwidth
       name: homebrew-tap
+      branch: "band-{{.Version}}"
       token: "{{ .Env.HOMEBREW_TAP_TOKEN }}"
       pull_request:
         enabled: true
         base:
-          owner: Bandwidth
-          name: homebrew-tap
           branch: main
     homepage: "https://github.com/Bandwidth/cli"
     description: "Bandwidth CLI — manage voice, messaging, numbers, and more from the command line"