Allow to set branch mode in tinybird.config.json

[manumartinm]

This MR releases tinybird-sdk-python version 0.1.11 and aligns the SDK with Tinybird CLI 4.6.1 branch-management behavior.

Changes

• Bumped package version to 0.1.11.
• Updated bundled CLI dependency to tinybird==4.6.1.
• Updated CHANGELOG.md with release notes for 0.1.11.

Included CLI behavior updates (4.6.1)

• branch_data_on_create is replaced by branch_data_mode; legacy key now raises an explicit migration error.
• branch_data_mode now only accepts last_partition as user-facing value.
• In dev_mode=local, branch data mode warnings are shown only when branch_data_mode is explicitly set in tinybird.config.json.
• tinybird branch create and tinybird branch clear now show a deprecation warning (instead of failing) when --ignore-datasource is passed, then continue by ignoring the flag.

Why

To keep Python SDK users aligned with current CLI semantics and avoid failures in branch flows that now require warning-and-continue behavior.

[juliavallina]

MR title is not correct, right? can we add a MR description also?
And also, we should update docs/changelog/readme, right? how users are going to discover and use this new setting?