Update checkout action to v4 based on code review

Co-authored-by: dibarbet <5749229+dibarbet@users.noreply.github.com>

Author: Copilot

.github/workflows/branch-snap.yml

@@ -24,7 +24,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Check out
-        uses: actions/checkout@v2
+        uses: actions/checkout@v4
       - name: Install NodeJS
         uses: actions/setup-node@v4
         with:
@@ -52,7 +52,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Check out merge branch
-        uses: actions/checkout@v2
+        uses: actions/checkout@v4
         with:
           ref: merge/prerelease-to-release
           fetch-depth: 0