Add emoji to GitHub Actions step names for consistency

Several workflows were missing the emoji-prefixed step naming used
elsewhere (e.g. nightly-build.yml, build-submit-ios/android.yml), and
a couple of files that already used emoji had a few gaps. Fills those
in across all workflow files. Job-level `name:` fields are left
untouched since some are pinned as required branch-protection check
names.

.github/workflows/zizmor.yml

@@ -20,12 +20,12 @@ jobs:
     name: Audit workflows with zizmor
     runs-on: ubuntu-latest
     steps:
-      - name: Check out Git repository
+      - name: ⬇️ Check out Git repository
         uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7.0.0
         with:
           persist-credentials: false
 
-      - name: Run zizmor
+      - name: 🛡️ Run zizmor
         uses: zizmorcore/zizmor-action@192e21d79ab29983730a13d1382995c2307fbcaa # v0.5.7
         with:
           # Annotate the PR directly instead of uploading SARIF to the