[Bug]: Abseil Cpp flags are not set in OSS from Python

### Describe the issue

Hi team,

This is basically a duplication of https://github.com/abseil/abseil-py/issues/200

The issue is that in OSS version of Abseil I can't set Abseil flags from command line when driving python binary build with Abseil Py modules (including unittest). This is especially problematic since Abseil logging library supports flags for runtime configuration and I can't use them with Python tests.

Is there any chance Abseil team can address this or recommend a simple way to work around this in OSS?

### Steps to reproduce the problem

Any Python unit test build with Abseil Py unittest module.

### What version of Abseil are you using?

Latest LTS

### What operating system and version are you using?

Linux

### What compiler and version are you using?

clang version 19.1.7

### What build system are you using?

bazel 8.1

### Additional context

_No response_