docs: trim PhysicalOptimizerRuleExportable docstring

Drop the sentence about logical-rule FFI availability; it is background, not type-hint information, and keeps the Protocol docstring in line with the other *Exportable hints.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: timsaucer

python/datafusion/context.py

@@ -134,9 +134,7 @@ class PhysicalOptimizerRuleExportable(Protocol):
     """Type hint for object that has __datafusion_physical_optimizer_rule__ PyCapsule.
 
     The method returns a PyCapsule wrapping an ``FFI_PhysicalOptimizerRule``,
-    typically produced by a separate compiled extension. DataFusion provides no
-    FFI bridge for logical optimizer or analyzer rules, so only physical
-    optimizer rules can be supplied this way.
+    typically produced by a separate compiled extension.
     """
 
     def __datafusion_physical_optimizer_rule__(self) -> object: ...  # noqa: D105