ci: publish: Fix SC2086 shellcheck warnings

Warnings were:

   $ brew style lyraphase/right2repair
   ../../../../../usr/local/Homebrew/Library/Taps/lyraphase/homebrew-right2repair/.github/workflows/publish.yml:39:9: shellcheck reported issue in this script: SC2086:info:6:9: Double quote to prevent globbing and word splitting [shellcheck]
      |
   39 |         run: |
      |         ^~~~
   ../../../../../usr/local/Homebrew/Library/Taps/lyraphase/homebrew-right2repair/.github/workflows/publish.yml:39:9: shellcheck reported issue in this script: SC2086:info:7:16: Double quote to prevent globbing and word splitting [shellcheck]
      |
   39 |         run: |
      |         ^~~~
   ../../../../../usr/local/Homebrew/Library/Taps/lyraphase/homebrew-right2repair/.github/workflows/publish.yml:39:9: shellcheck reported issue in this script: SC2086:info:11:3: Double quote to prevent globbing and word splitting [shellcheck]
      |
   39 |         run: |
      |         ^~~~

.github/workflows/publish.yml

@@ -42,12 +42,12 @@ jobs:
             --no-upload \
             --clean \
             --autosquash \
-            --tap=$GITHUB_REPOSITORY \
-            --github-org=${GITHUB_REPOSITORY_OWNER} \
+            --tap="$GITHUB_REPOSITORY" \
+            --github-org="${GITHUB_REPOSITORY_OWNER}" \
             --committer="$BREWTESTBOT_NAME_EMAIL" \
             --root-url="https://ghcr.io/v2/${GITHUB_REPOSITORY_OWNER}/${GITHUB_REPOSITORY#*/homebrew-}" \
             --retain-bottle-dir \
-            $PULL_REQUEST
+            "$PULL_REQUEST"
 
       - name: Generate build provenance
         uses: actions/attest-build-provenance@v1