lambda: prevent concurrent healthchecks reaching weblogs

[florentinl]

Motivation

lambda weblogs sometimes crash at startup with the following error (https://github.com/DataDog/dd-trace-py/actions/runs/19964031043/job/57251895120?pr=15525):

19 Nov 2025 20:05:07,663 [INFO] (rapid) INVOKE START(requestId: 8a0d6d43-3aeb-44db-a03f-c9a358933d01)
19 Nov 2025 20:05:08,131 [INFO] (rapid) ReserveFailed: AlreadyReserved
panic: runtime error: invalid memory address or nil pointer dereference
[signal SIGSEGV: segmentation violation code=0x1 addr=0x40 pc=0x785c7f]

This happens when the lambda emulator receives multiple requests at the same time (see this issue: aws/aws-lambda-runtime-interface-emulator#97).

At startup, the only requests that are sent are the healthchecks:

• to the lambda weblog directly
• to the lambda proxy which proxies the healthcheck to the lambda weblog.

To avoid healthchecks conflicts, the lambda proxy shouldn't relay the healthcheck to the lambda weblog as both containers are tested independently.

Changes

• stop proxying healthcheck requests in lambda-proxy

Workflow

1. ⚠️ Create your PR as draft ⚠️
2. Work on you PR until the CI passes
3. Mark it as ready for review
   • Test logic is modified? -> Get a review from RFC owner.
   • Framework is modified, or non obvious usage of it -> get a review from R&P team

🚀 Once your PR is reviewed and the CI green, you can merge it!

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Reviewer checklist

• If PR title starts with [<language>], double-check that only <language> is impacted by the change
• No system-tests internal is modified. Otherwise, I have the approval from R&P team
• A docker base image is modified?
  • the relevant build-XXX-image label is present
• A scenario is added (or removed)?
  • Get a review from R&P team

[github-actions]

CODEOWNERS have been resolved as:

utils/build/docker/lambda_proxy/main.py                                 @DataDog/system-tests-core