Extend packet at the sock msg level

[rafaelroquetto]

Instead of relying on TC to write the Traceparent: header, leverage beyla_packet_extender at the sk_msg level to not only extend the request buffer, but also write the Traceparent: string at that level.
This ensures that the request buffer is manipulated only once, by a single ebpf program, and prevents corrupt requests that can be caused if one of the programs involved fails to attach.

The TC programs are now only responsible for writing the IP options, and only if the Traceparent: header hasn't been written by the sk_msg program. This is done because the IP injection mechanism derives the span id from the tcp seq and ack values, which are not yet available at the sk_msg level.

The TC programs will also continue to track any new sockets that haven't been picked up by the sockops program.

[codecov]

Codecov Report

Attention: Patch coverage is 80.00000% with 3 lines in your changes missing coverage. Please review.

Project coverage is 66.98%. Comparing base (7dbd664) to head (9b7ec92).
Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
pkg/internal/ebpf/tctracer/tctracer.go	80.00%	2 Missing and 1 partial ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1740      +/-   ##
==========================================
- Coverage   66.99%   66.98%   -0.02%     
==========================================
  Files         214      214              
  Lines       22241    22244       +3     
==========================================
- Hits        14901    14900       -1     
- Misses       6605     6607       +2     
- Partials      735      737       +2     

Flag	Coverage Δ
integration-test	54.46% <80.00%> (+0.40%)	⬆️
k8s-integration-test	53.93% <80.00%> (-0.10%)	⬇️
oats-test	34.93% <80.00%> (+0.08%)	⬆️
unittests	43.86% <0.00%> (-0.01%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.
• 📦 JS Bundle Analysis: Save yourself from yourself by tracking and limiting bundle sizes in JS merges.

[mariomac]

amazing! I'd suggest backporting it to 2.0 branch

[grcevski]

Looks amazing, I do have one concern about removing the sock from the map, but I might be misunderstanding the intent.

[rafaelroquetto]

Merging as I've discussed this offline and incorporated the latest feedback.