Re-remove iast .so file.

[purple4reina]

Commit DataDog/dd-trace-py@fa18def was merged to address this.

What does this PR do?

Re-removes the ddtrace/appsec/_iast/_stacktrace*.so file from our python layers.

Motivation

A change was made by the appsec team to the python tracer which inadvertently caused an import attempt on ddtrace/appsec/_iast/_stacktrace*.so. This import would fail when using our python layer. We remove this file because it is large and iast doesn't work in serverless anyway.

I worked with the appsec team directly to address this. They came up with a solution that not only ensures we don't import ddtrace/appsec/_iast/_stacktrace*.so, but also makes sure no iast code is imported when iast is disabled.

Now that DataDog/dd-trace-py#12212 is merged, we can go back to safely removing this .so file in our layers.

Testing Guidelines

I have another PR open to the python agent (DataDog/dd-trace-py#11888) which will add explicit testing to ensure none of our removed files get imported.

Additional Notes

Note that the mentioned PR is merged but not yet released! Do not merge this until that PR has been released!

Types of Changes

• Bug fix
• New feature
• Breaking change
• Misc (docs, refactoring, dependency upgrade, etc.)

Check all that apply

• This PR's description is comprehensive
• This PR contains breaking changes that are documented in the description
• This PR introduces new APIs or parameters that are documented and unlikely to change in the foreseeable future
• This PR impacts documentation, and it has been updated (or a ticket has been logged)
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