GitHub Actions nightly crash test runs on ARM (facebook#14172)

Summary:
To help find potential issues not showing up in ARM unit tests. I'm running it with and without TransactionDB (write-committed) for better coverage. The job expands the size of /dev/shm for adequate space on maximum performance storage, and adds swap space to reduce risk of OOM in case we fill that up.

Pull Request resolved: facebook#14172

Test Plan: earlier drafts of this PR added the job to PR jobs, and the last before putting in "nightly" can be seen here: https://github.com/facebook/rocksdb/actions/runs/19945493840/job/57193797390?pr=14172

Reviewed By: archang19

Differential Revision: D88429479

Pulled By: pdillinger

fbshipit-source-id: bd4d9cda9256950c3c6c126c299a44dbbbc30c7e

Author: pdillinger

.github/workflows/nightly.yml

@@ -110,6 +110,20 @@ jobs:
       - run: sudo apt-get update && sudo apt-get install -y build-essential libgflags-dev
       - run: make V=1 J=4 -j4 check
       - uses: "./.github/actions/post-steps"
+  build-linux-arm-crashtest:
+    if: ${{ github.repository_owner == 'facebook' }}
+    runs-on:
+      labels: 4-core-ubuntu-arm
+    steps:
+    - uses: actions/checkout@v4.1.0
+    - uses: "./.github/actions/pre-steps"
+    - run: sudo apt-get update && sudo apt-get install -y build-essential libgflags-dev libsnappy-dev zlib1g-dev libbz2-dev liblz4-dev libzstd-dev
+    - run: sudo mount -o remount,size=16G /dev/shm
+    - run: sudo dd bs=1048576 count=4096 if=/dev/zero of=/swapfile && sudo chmod 600 /swapfile && sudo mkswap /swapfile && sudo swapon /swapfile
+    - run: ulimit -S -n `ulimit -H -n` && make V=1 -j8 CRASH_TEST_EXT_ARGS='--duration=1800 --max_key=2500000' blackbox_crash_test_with_atomic_flush
+    - run: rm -rf /dev/shm/rocksdb.*
+    - run: ulimit -S -n `ulimit -H -n` && make V=1 -j8 CRASH_TEST_EXT_ARGS='--duration=1800 --max_key=2500000' blackbox_crash_test_with_multiops_wc_txn
+    - uses: "./.github/actions/post-steps"
   build-examples:
     if: ${{ github.repository_owner == 'facebook' }}
     runs-on: