Goal

Unblock the CI

Why

Currently there are two issues:

1. clang-format-action started failing in the CI. Example failure: https://github.com/aws/s2n-tls/actions/runs/22070958724/job/63775094798The issue is being tracked in the mainline repo: action suddenly no longer available from docker on GitHub actions jidicula/clang-format-action#267
2. pcap test is failing due to xml parsing failure. Example failure: https://github.com/aws/s2n-tls/actions/runs/22070958716/job/63775094672

How

This PR unblocks the CI by:

1. Replacing the action with a script that installs clang-format-18 natively then run the same logic as clang-format-action (find files matching the include regex, run clang-format --dry-run --Werror on each one, report failures).
2. pinning the rtshark version. I suspect this is caused by stricter xml parsing behavior introduced by quick-xml v3.9(dependency of rtshark). I created a public issue to request insight: rtshark 4.2.0: "tag not closed" XML parsing errors when reading from tshark CrabeDeFrance/rtshark#40

Callouts

These are temporary changes to unblock CI. Revert once respective issues are resolved.

Testing

Tests are now passing

Related

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