Update Bazel abseil-py to 1.2.0 or newer

### Description of the feature request:

I wanted to start this issue to discuss about the update of the abseil-py inside the third_party folder.
The current [version used is 0.1.1](https://github.com/bazelbuild/bazel/blob/master/third_party/py/abseil/README.md) that was release [on October 2017 (5 years ago)](https://pypi.org/project/absl-py/0.1.1/).
I came up to that because I was checking why there is still six in third_party folder, and basically is needed for abseil-py.
Version 1.1.0 of abseil-py [do no longer need six](https://github.com/abseil/abseil-py/releases/tag/v1.1.0).
Version 1.2.0 [has only a fix](https://github.com/abseil/abseil-py/releases/tag/v1.2.0), that is why it would make sense to update it to 1.2.0 or newer.

### What underlying problem are you trying to solve with this feature?

- Not have dependencies that are 5 years old
- Be able to remove six [from third_party folder](https://github.com/bazelbuild/bazel/tree/master/third_party/py/six)

### Which operating system are you running Bazel on?

Irrelevant

### What is the output of `bazel info release`?

master

### If `bazel info release` returns `development version` or `(@non-git)`, tell us how you built Bazel.

_No response_

### What's the output of `git remote get-url origin; git rev-parse master; git rev-parse HEAD` ?

_No response_

### Have you found anything relevant by searching the web?

_No response_

### Any other information, logs, or outputs that you want to share?

_No response_

The dependency is documented in third_party/py/abseil/README.md; start there and inspect the related files under third_party/py/abseil and third_party/py/six. Update abseil-py to 1.2.0 or newer, remove six if it is no longer needed, and verify the Bazel build remains consistent.

Written by the indexing model from the issue text.