[CI] Align PD tests to HMA on by default

[NickLucche]

#41847 switched HMA from opt-in to opt-out, completing its experimental cycle.
Connectors that support it will now have it turned on by default unless otherwise specified.

This PR is a follow up to that to make sure our CI for the PD related tests is aligned to this, moving to testing the auto behavior rather than explicitely turning HMA on with --no-disable-hybrid-kv-cache-manager

[mergify]

Hi @NickLucche, the pre-commit checks have failed. Please run:

uv pip install pre-commit>=4.5.1
pre-commit install
pre-commit run --all-files

Then, commit the changes and push to your branch.

For future commits, pre-commit will run automatically on changed files before each commit.

Tip

Is mypy failing?

mypy is run differently in CI. If the failure is related to this check, please use the following command to run it locally:

# For mypy (substitute "3.10" with the failing version if needed)
pre-commit run --hook-stage manual mypy-3.10