fix(ci): fix bugs in Homebrew testing

* Use -i to modify the file instead of just printing it.
* Fix the search term to match what's in the original file. Otherwise,
  no change actually happens.

.github/workflows/test-homebrew-package.yml

@@ -32,7 +32,7 @@ jobs:
         run: |
           set -x
           formula_path="$(brew formula quick-lint/quick-lint-js/quick-lint-js)"
-          sed -e 's,:branch => "master",:revision => "'"$(git rev-parse HEAD)"'",' "${formula_path}"
+          sed -i -e 's,branch: "master",revision: "'"$(git rev-parse HEAD)"'",' "${formula_path}"
           printf 'updated formula:\n'
           cat "${formula_path}"