fix: use correct install path in homebrew formula template (#3)

The formula uses archive tarball URL where the script is at bin/git-wt,
not at the root. This fixes the "No such file or directory - git-wt"
error when installing via homebrew.

Co-authored-by: Claude Code (User Settings, in: ${CLAUDE_PROJECT_DIR}) <noreply@anthropic.com>

Author: nsheaps

.github/workflows/release.yaml

@@ -141,11 +141,7 @@ jobs:
             depends_on 'gum'
 
             def install
-              if build.head?
-                bin.install 'bin/git-wt'
-              else
-                bin.install 'git-wt'
-              end
+              bin.install 'bin/git-wt'
             end
 
             test do