ci(refactor): remove Valgrind checks from omnibus and generalBatch

[boquan-fang]

Description of changes:

Our CIs for github and release runs Valgrind in generalBatch/Omnibus and Valgrind Codebuild job. Since a separate Valgrind test has been fully integrated into the github CI and the release CI, Valgrind in generalBatch and Omnibus should be removed.

• Remove buildspecs for Valgrind tests in buildspec_omnibus.yml and buildspec_generalbatch.yml.
• Remove Valgrind in Makefiles and s2n_codebuild.sh.

Call-outs:

• This is a follow up PR for PR#4912.
  • This PR can be merged after the previous PR is merged.
• The s2nOmnibus job's inline buildspec is out of date from buildspec_omnibus.yml. I synced the inline buildspec for s2nOmnibus to buildspec_omnibus.yml to make them consistent.
• Our s2nOmnibus job takes in line buildspec. I need to manually copy and paste buildspec_omnibus.yml to the Codebuild job after this PR is merged.

Testing:

Test by CI for the refactored GeneralBatch job.

Test for this refactored buildspec_omnibus.yml can be found in this codebuild job.

The triggered Valgrind job can be found here.

The triggered S2nIntegrationV2Batch2 test can be found in this job.

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

[dougch]

Looks good, I just want to see one attempt to run this new Omnibus, we can sync up tomorrow (or add a link to the overview)

[boquan-fang]

I have attached the links for triggered Omnibus, Valgrind, and Integration tests to the Testing section of the PR descriptions.

[maddeleine]

This LGTM, but I would recommend getting Doug's approval on this. I'm pretty sure only he can verify the source of truth for the buildspec_omnibus.