fix(block-dynamic-connection): recache connection pairs after dynamically adding inputs

[mikeharv]

The basics

• I validated my changes

The details

Resolves

Fixes #2708
Depends upon:

• feat: make cacheAllConnectionPairs public blockly#10149

Proposed Changes

After onPendingConnection(), if the dynamic block has new inputs, re-cache the compatible connection pairs for the currently dragging block.

Reason for Changes

As stated in the issue:

When using block-dynamic-connection with Blockly v13, and moving blocks via the keyboard, new connections are correctly added to blocks, but because move mode pre-caches the list of available connections at the start of a keyboard-driven move, they are not offered as connection points in constrained move mode.

This fixes this issue.

Test Coverage

No plugin-level tests were added for this change. A headless test would only verify mocked interactions and would not meaningfully exercise constrained movement. Testing the complete behavior with rendered blocks would require substantial browser, rendering, and drag-state setup disproportionate to the small plugin change.

Instead, Blockly core tests cover the important behavioral contract: after cacheAllConnectionPairs() is called during a move, newly added connections are included in the cache and can be visited in the expected traversal order.

Documentation

Additional Information

This depends upon BlockDragStrategy.cacheAllConnectionPairs being made public, so this should only be merged after RaspberryPiFoundation/blockly#10149 is merged and, ideally, released.