chore: add workflow to verify that files are in LFS (#34727)

Our GitHub repository has 77 files that should have been in LFS, but aren't because a contributor didn't install LFS before contributing.

This is an easy mistake to make.

Add a GitHub workflow that will fail if there are any files that should have been in LFS, but aren't.

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*By submitting this pull request, I confirm that my contribution is made under the terms of the Apache-2.0 license*

Author: rix0rrr

.github/workflows/check-lfs.yml

@@ -0,0 +1,15 @@
+name: Check all requires files are in LFS
+on:
+  pull_request: {}
+
+jobs:
+  check-lfs:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Check out repository
+        uses: actions/checkout@v4
+        with:
+          # We don't actually care about LFS file contents, just their integrity.
+          lfs: false
+      - name: Check LFS pointers
+        run: git lfs fsck --pointers