[nfc] alias tf_agents.policies.policy_saver as tf_policy_saver

[cnaples79]

Summary

• Import tf_agents.policies.policy_saver as tf_policy_saver
• Update usages and type hints to use tf_policy_saver.PolicySaver

This clarifies that MLGOPolicySaver is our wrapper, and PolicySaver refers to TF-Agents.

Refs #309

[mtrofin]

Thanks - can you please rename the title with the prefix [nfc] (a'la LLVM. Signals to reviewers that "no tests needed")

Could you also reduce the message to e.g. what you have in the commit (pasted below for clarity)? Was the current commit message AI-generated? It's missing text, e.g. "Import TF‑Agents policy saver as .". Anyway, no need for overly-formatted stuff, the simpler message is perfect!

- Import tf_agents.policies.policy_saver as tf_policy_saver
- Update usages and type hints to use tf_policy_saver.PolicySaver

This clarifies that MLGOPolicySaver is our wrapper, and PolicySaver refers to TF-Agents.

Thanks!

[cnaples79]

@mtrofin should be fixed! Let me know if I need to make any other changes.

[mtrofin]

@mtrofin should be fixed! Let me know if I need to make any other changes.

The commit message?

[cnaples79]

@mtrofin I updated both the PR body and the commit message. Is it still not showing as changed?

[mtrofin]

@mtrofin I updated both the PR body and the commit message. Is it still not showing as changed?

Does now - thank you!