Workaround for Github's Ubuntu image getting spurious Asan failures (#…

…5557)

### What

Hitting some spurious asan issues on ci: Some Linux runs end up spamming
`AddressSanitizer:DEADLYSIGNAL` indefinitely with no additional
information.

Originally I suspected this came from
* #5544

But it's actually a Github image issue, see
actions/runner-images#9491

### Checklist
* [x] I have read and agree to [Contributor
Guide](https://github.com/rerun-io/rerun/blob/main/CONTRIBUTING.md) and
the [Code of
Conduct](https://github.com/rerun-io/rerun/blob/main/CODE_OF_CONDUCT.md)
* [x] I've included a screenshot or gif (if applicable)
* [x] I have tested the web demo (if applicable):
* Using newly built examples:
[app.rerun.io](https://app.rerun.io/pr/5557/index.html)
* Using examples from latest `main` build:
[app.rerun.io](https://app.rerun.io/pr/5557/index.html?manifest_url=https://app.rerun.io/version/main/examples_manifest.json)
* Using full set of examples from `nightly` build:
[app.rerun.io](https://app.rerun.io/pr/5557/index.html?manifest_url=https://app.rerun.io/version/nightly/examples_manifest.json)
* [x] The PR title and labels are set such as to maximize their
usefulness for the next release's CHANGELOG
* [x] If applicable, add a new check to the [release
checklist](https://github.com/rerun-io/rerun/blob/main/tests/python/release_checklist)!

- [PR Build Summary](https://build.rerun.io/pr/5557)
- [Docs
preview](https://rerun.io/preview/8ac1180d749f9bf9ae62ee57f96c66c832758a9d/docs)
<!--DOCS-PREVIEW-->
- [Examples
preview](https://rerun.io/preview/8ac1180d749f9bf9ae62ee57f96c66c832758a9d/examples)
<!--EXAMPLES-PREVIEW-->
- [Recent benchmark results](https://build.rerun.io/graphs/crates.html)
- [Wasm size tracking](https://build.rerun.io/graphs/sizes.html)

.github/workflows/reusable_checks_cpp.yml

@@ -84,6 +84,14 @@ jobs:
           workload_identity_provider: ${{ secrets.GOOGLE_WORKLOAD_IDENTITY_PROVIDER }}
           service_account: ${{ secrets.GOOGLE_SERVICE_ACCOUNT }}
 
+      # Workaround for ASAN issues on Github images https://github.com/actions/runner-images/issues/9491
+      - name: Fix kernel mmap rnd bits
+        if: runner.os == 'Linux'
+        # Asan in llvm 14 provided in ubuntu 22.04 is incompatible with
+        # high-entropy ASLR in much newer kernels that GitHub runners are
+        # using leading to random crashes: https://reviews.llvm.org/D148280
+        run: sudo sysctl vm.mmap_rnd_bits=28
+
       - name: Build and run C++ tests
         shell: bash
         run: |