ci: Add test workflow to reproduce upload-artifact failure on macOS

Add a workflow to try to reproduce the failure we see in teleport.e with
upload-artifact on macOS, reported in
actions/upload-artifact#527.

Reproducing this in a public repo with minimal steps will make it easier
to diagnose this issue.

.github/workflows/mac-upload-artifact.yaml

@@ -0,0 +1,23 @@
+name: Reproduce Mac upload-artifact failure
+on:
+  push:
+    branches:
+      - camh/repro-mac-upload-artifact-issue
+
+jobs:
+  test-upload-artifact:
+    runs-on: macos-13-xl-arm64
+    steps:
+      - name: Create files (100MiB)
+        run: |
+          dd if=/dev/urandom of=artifact bs=1M count=100
+          dd if=/dev/zero of=artifact-unsigned bs=1M count=1
+      - name: upload artifact
+        uses: actions/upload-artifact@v4
+        with:
+          name: urandom
+          compression-level: 0
+          retention-days: 1
+          path: |
+            artifact
+            !*-unsigned*