workflows/sorbet: Rename from Tapioca as it does more than Tapioca now

- This uses the `--update` switch to do both RBI file updates and pruning of
  deleted files from `sorbet/files.yaml`. The assumption is that only
  this automated task will run this command.

.github/workflows/tapioca.yml → .github/workflows/sorbet.yml

-name: Update Tapioca definitions
+name: Update Sorbet-related files
 on:
   push:
     paths:
-      - .github/workflows/tapioca.yml
+      - .github/workflows/sorbet.yml
     branches-ignore:
       - master
   schedule:
@@ -26,7 +26,7 @@ jobs:
         run: |
           git fetch origin
 
-          BRANCH="tapioca-update"
+          BRANCH="sorbet-files-update"
           echo "::set-output name=branch::${BRANCH}"
 
           if git ls-remote --exit-code --heads origin "$BRANCH"; then
@@ -37,9 +37,9 @@ jobs:
             BRANCH_EXISTS="1"
           fi
 
-          if brew typecheck --prune-files-list --update-definitions --fail-if-not-changed; then
+          if brew typecheck --update --fail-if-not-changed; then
             git add "$GITHUB_WORKSPACE/Library/Homebrew/sorbet"
-            git commit -m "sorbet: update RBI files using Tapioca." -m "Autogenerated by [a scheduled GitHub Action](https://github.com/Homebrew/brew/blob/master/.github/workflows/tapioca.yml)."
+            git commit -m "sorbet: Update RBI files and prune files.yaml." -m "Autogenerated by [a scheduled GitHub Action](https://github.com/Homebrew/brew/blob/master/.github/workflows/sorbet.yml)."
             echo "::set-output name=committed::true"
             if [ -n "$BRANCH_EXISTS" ]; then
               echo "::set-output name=pull_request::true"